sys/ofed/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
  35 #include <linux/mm.h>
  36 #include <linux/scatterlist.h>
  37 #include <linux/sched.h>
  38
  39 #include <asm/page.h>
  40
  41 #include "mthca_memfree.h"
  42 #include "mthca_dev.h"
  43 #include "mthca_cmd.h"
  44
  45 /*
  46  * We allocate in as big chunks as we can, up to a maximum of 256 KB
  47  * per chunk.
  48  */
  49 enum {
  50         MTHCA_ICM_ALLOC_SIZE   = 1 << 18,
  51         MTHCA_TABLE_CHUNK_SIZE = 1 << 18
  52 };
  53
  54 struct mthca_user_db_table {
  55         struct mutex mutex;
  56         struct {
  57                 u64                uvirt;
  58                 struct scatterlist mem;
  59                 int                refcount;
  60         }                page[0];
  61 };
  62
  63 static void mthca_free_icm_pages(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
  64 {
  65         int i;
  66
  67         if (chunk->nsg > 0)
  68                 pci_unmap_sg(dev->pdev, chunk->mem, chunk->npages,
  69                              PCI_DMA_BIDIRECTIONAL);
  70
  71         for (i = 0; i < chunk->npages; ++i)
  72                 __free_pages(sg_page(&chunk->mem[i]),
  73                              get_order(chunk->mem[i].length));
  74 }
  75
  76 static void mthca_free_icm_coherent(struct mthca_dev *dev, struct mthca_icm_chunk *chunk)
  77 {
  78         int i;
  79
  80         for (i = 0; i < chunk->npages; ++i) {
  81                 dma_free_coherent(&dev->pdev->dev, chunk->mem[i].length,
  82                                   lowmem_page_address(sg_page(&chunk->mem[i])),
  83                                   sg_dma_address(&chunk->mem[i]));
  84         }
  85 }
  86
  87 void mthca_free_icm(struct mthca_dev *dev, struct mthca_icm *icm, int coherent)
  88 {
  89         struct mthca_icm_chunk *chunk, *tmp;
  90
  91         if (!icm)
  92                 return;
  93
  94         list_for_each_entry_safe(chunk, tmp, &icm->chunk_list, list) {
  95                 if (coherent)
  96                         mthca_free_icm_coherent(dev, chunk);
  97                 else
  98                         mthca_free_icm_pages(dev, chunk);
  99
 100                 kfree(chunk);
 101         }
 102
 103         kfree(icm);
 104 }
 105
 106 static int mthca_alloc_icm_pages(struct scatterlist *mem, int order, gfp_t gfp_mask)
 107 {
 108         struct page *page;
 109
 110         /*
 111          * Use __GFP_ZERO because buggy firmware assumes ICM pages are
 112          * cleared, and subtle failures are seen if they aren't.
 113          */
 114         page = alloc_pages(gfp_mask | __GFP_ZERO, order);
 115         if (!page)
 116                 return -ENOMEM;
 117
 118         sg_set_page(mem, page, PAGE_SIZE << order, 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 obj_per_chunk;
 365         int num_icm;
 366         unsigned chunk_size;
 367         int i;
 368         u8 status;
 369
 370         obj_per_chunk = MTHCA_TABLE_CHUNK_SIZE / obj_size;
 371         num_icm = DIV_ROUND_UP(nobj, obj_per_chunk);
 372
 373         table = kmalloc(sizeof *table + num_icm * sizeof *table->icm, GFP_KERNEL);
 374         if (!table)
 375                 return NULL;
 376
 377         table->virt     = virt;
 378         table->num_icm  = num_icm;
 379         table->num_obj  = nobj;
 380         table->obj_size = obj_size;
 381         table->lowmem   = use_lowmem;
 382         table->coherent = use_coherent;
 383         mutex_init(&table->mutex);
 384
 385         for (i = 0; i < num_icm; ++i)
 386                 table->icm[i] = NULL;
 387
 388         for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
 389                 chunk_size = MTHCA_TABLE_CHUNK_SIZE;
 390                 if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
 391                         chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
 392
 393                 table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
 394                                                 (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
 395                                                 __GFP_NOWARN, use_coherent);
 396                 if (!table->icm[i])
 397                         goto err;
 398                 if (mthca_MAP_ICM(dev, table->icm[i], virt + i * MTHCA_TABLE_CHUNK_SIZE,
 399                                   &status) || status) {
 400                         mthca_free_icm(dev, table->icm[i], table->coherent);
 401                         table->icm[i] = NULL;
 402                         goto err;
 403                 }
 404
 405                 /*
 406                  * Add a reference to this ICM chunk so that it never
 407                  * gets freed (since it contains reserved firmware objects).
 408                  */
 409                 ++table->icm[i]->refcount;
 410         }
 411
 412         return table;
 413
 414 err:
 415         for (i = 0; i < num_icm; ++i)
 416                 if (table->icm[i]) {
 417                         mthca_UNMAP_ICM(dev, virt + i * MTHCA_TABLE_CHUNK_SIZE,
 418                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 419                                         &status);
 420                         mthca_free_icm(dev, table->icm[i], table->coherent);
 421                 }
 422
 423         kfree(table);
 424
 425         return NULL;
 426 }
 427
 428 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table)
 429 {
 430         int i;
 431         u8 status;
 432
 433         for (i = 0; i < table->num_icm; ++i)
 434                 if (table->icm[i]) {
 435                         mthca_UNMAP_ICM(dev, table->virt + i * MTHCA_TABLE_CHUNK_SIZE,
 436                                         MTHCA_TABLE_CHUNK_SIZE / MTHCA_ICM_PAGE_SIZE,
 437                                         &status);
 438                         mthca_free_icm(dev, table->icm[i], table->coherent);
 439                 }
 440
 441         kfree(table);
 442 }
 443
 444 static u64 mthca_uarc_virt(struct mthca_dev *dev, struct mthca_uar *uar, int page)
 445 {
 446         return dev->uar_table.uarc_base +
 447                 uar->index * dev->uar_table.uarc_size +
 448                 page * MTHCA_ICM_PAGE_SIZE;
 449 }
 450
 451
 452 #include <vm/vm_map.h>
 453 #include <vm/vm_pageout.h>
 454 #include <vm/pmap.h>
 455
 456 #include <sys/resource.h>
 457 #include <sys/resourcevar.h>
 458
 459 int mthca_map_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 460                       struct mthca_user_db_table *db_tab, int index, u64 uaddr)
 461 {
 462 #ifdef __linux__
 463         struct page *pages[1];
 464         int ret = 0;
 465         u8 status;
 466         int i;
 467
 468         if (!mthca_is_memfree(dev))
 469                 return 0;
 470
 471         if (index < 0 || index > dev->uar_table.uarc_size / 8)
 472                 return -EINVAL;
 473
 474         mutex_lock(&db_tab->mutex);
 475
 476         i = index / MTHCA_DB_REC_PER_PAGE;
 477
 478         if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
 479             (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
 480             (uaddr & 4095)) {
 481                 ret = -EINVAL;
 482                 goto out;
 483         }
 484
 485         if (db_tab->page[i].refcount) {
 486                 ++db_tab->page[i].refcount;
 487                 goto out;
 488         }
 489
 490         ret = get_user_pages(current, current->mm, uaddr & PAGE_MASK, 1, 1, 0,
 491                              pages, NULL);
 492         if (ret < 0)
 493                 goto out;
 494
 495         sg_set_page(&db_tab->page[i].mem, pages[0], MTHCA_ICM_PAGE_SIZE,
 496                         uaddr & ~PAGE_MASK);
 497
 498         ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 499         if (ret < 0) {
 500                 put_page(pages[0]);
 501                 goto out;
 502         }
 503
 504         ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
 505                                  mthca_uarc_virt(dev, uar, i), &status);
 506         if (!ret && status)
 507                 ret = -EINVAL;
 508         if (ret) {
 509                 pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 510                 put_page(sg_page(&db_tab->page[i].mem));
 511                 goto out;
 512         }
 513
 514         db_tab->page[i].uvirt    = uaddr;
 515         db_tab->page[i].refcount = 1;
 516
 517 out:
 518         mutex_unlock(&db_tab->mutex);
 519         return ret;
 520 #else
 521         struct proc *proc;
 522         vm_offset_t start;
 523         vm_paddr_t paddr;
 524         pmap_t pmap;
 525         vm_page_t m;
 526         int ret = 0;
 527         u8 status;
 528         int i;
 529
 530         if (!mthca_is_memfree(dev))
 531                 return 0;
 532
 533         if (index < 0 || index > dev->uar_table.uarc_size / 8)
 534                 return -EINVAL;
 535
 536         mutex_lock(&db_tab->mutex);
 537
 538         i = index / MTHCA_DB_REC_PER_PAGE;
 539         start = 0;
 540
 541         if ((db_tab->page[i].refcount >= MTHCA_DB_REC_PER_PAGE)       ||
 542             (db_tab->page[i].uvirt && db_tab->page[i].uvirt != uaddr) ||
 543             (uaddr & 4095)) {
 544                 ret = -EINVAL;
 545                 goto out;
 546         }
 547
 548         if (db_tab->page[i].refcount) {
 549                 ++db_tab->page[i].refcount;
 550                 goto out;
 551         }
 552
 553         proc = curproc;
 554         pmap = vm_map_pmap(&proc->p_vmspace->vm_map);
 555         PROC_LOCK(proc);
 556         if (ptoa(pmap_wired_count(pmap) + 1) > lim_cur(proc, RLIMIT_MEMLOCK)) {
 557                 PROC_UNLOCK(proc);
 558                 ret = -ENOMEM;
 559                 goto out;
 560         }
 561         PROC_UNLOCK(proc);
 562         if (cnt.v_wire_count + 1 > vm_page_max_wired) {
 563                 ret = -EAGAIN;
 564                 goto out;
 565         }
 566         start = uaddr & PAGE_MASK;
 567         ret = vm_map_wire(&proc->p_vmspace->vm_map, start, start + PAGE_SIZE,
 568             VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES | VM_MAP_WIRE_WRITE);
 569         if (ret != KERN_SUCCESS) {
 570                 start = 0;
 571                 ret = -ENOMEM;
 572                 goto out;
 573         }
 574         paddr = pmap_extract(pmap, uaddr);
 575         if (paddr == 0) {
 576                 ret = -EFAULT;
 577                 goto out;
 578         }
 579         m = PHYS_TO_VM_PAGE(paddr);
 580
 581         sg_set_page(&db_tab->page[i].mem, m, MTHCA_ICM_PAGE_SIZE,
 582                         uaddr & ~PAGE_MASK);
 583
 584         ret = pci_map_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 585         if (ret < 0)
 586                 goto out;
 587
 588         ret = mthca_MAP_ICM_page(dev, sg_dma_address(&db_tab->page[i].mem),
 589                                  mthca_uarc_virt(dev, uar, i), &status);
 590         if (!ret && status)
 591                 ret = -EINVAL;
 592         if (ret) {
 593                 pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 594                 goto out;
 595         }
 596
 597         db_tab->page[i].uvirt    = uaddr;
 598         db_tab->page[i].refcount = 1;
 599
 600 out:
 601         if (ret < 0 && start)
 602                 vm_map_unwire(&curthread->td_proc->p_vmspace->vm_map,
 603                     start, start + PAGE_SIZE,
 604                     VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
 605         mutex_unlock(&db_tab->mutex);
 606         return ret;
 607 #endif
 608 }
 609
 610 void mthca_unmap_user_db(struct mthca_dev *dev, struct mthca_uar *uar,
 611                          struct mthca_user_db_table *db_tab, int index)
 612 {
 613         if (!mthca_is_memfree(dev))
 614                 return;
 615
 616         /*
 617          * To make our bookkeeping simpler, we don't unmap DB
 618          * pages until we clean up the whole db table.
 619          */
 620
 621         mutex_lock(&db_tab->mutex);
 622
 623         --db_tab->page[index / MTHCA_DB_REC_PER_PAGE].refcount;
 624
 625         mutex_unlock(&db_tab->mutex);
 626 }
 627
 628 struct mthca_user_db_table *mthca_init_user_db_tab(struct mthca_dev *dev)
 629 {
 630         struct mthca_user_db_table *db_tab;
 631         int npages;
 632         int i;
 633
 634         if (!mthca_is_memfree(dev))
 635                 return NULL;
 636
 637         npages = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 638         db_tab = kmalloc(sizeof *db_tab + npages * sizeof *db_tab->page, GFP_KERNEL);
 639         if (!db_tab)
 640                 return ERR_PTR(-ENOMEM);
 641
 642         mutex_init(&db_tab->mutex);
 643         for (i = 0; i < npages; ++i) {
 644                 db_tab->page[i].refcount = 0;
 645                 db_tab->page[i].uvirt    = 0;
 646                 sg_init_table(&db_tab->page[i].mem, 1);
 647         }
 648
 649         return db_tab;
 650 }
 651
 652 void mthca_cleanup_user_db_tab(struct mthca_dev *dev, struct mthca_uar *uar,
 653                                struct mthca_user_db_table *db_tab)
 654 {
 655         int i;
 656         u8 status;
 657
 658         if (!mthca_is_memfree(dev))
 659                 return;
 660
 661         for (i = 0; i < dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE; ++i) {
 662                 if (db_tab->page[i].uvirt) {
 663                         mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, uar, i), 1, &status);
 664                         pci_unmap_sg(dev->pdev, &db_tab->page[i].mem, 1, PCI_DMA_TODEVICE);
 665 #ifdef __linux__
 666                         put_page(sg_page(&db_tab->page[i].mem));
 667 #else
 668                         vm_offset_t start;
 669
 670                         start = db_tab->page[i].uvirt & PAGE_MASK;
 671                         vm_map_unwire(&curthread->td_proc->p_vmspace->vm_map,
 672                             start, start + PAGE_SIZE,
 673                             VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
 674 #endif
 675                 }
 676         }
 677
 678         kfree(db_tab);
 679 }
 680
 681 int mthca_alloc_db(struct mthca_dev *dev, enum mthca_db_type type,
 682                    u32 qn, __be32 **db)
 683 {
 684         int group;
 685         int start, end, dir;
 686         int i, j;
 687         struct mthca_db_page *page;
 688         int ret = 0;
 689         u8 status;
 690
 691         mutex_lock(&dev->db_tab->mutex);
 692
 693         switch (type) {
 694         case MTHCA_DB_TYPE_CQ_ARM:
 695         case MTHCA_DB_TYPE_SQ:
 696                 group = 0;
 697                 start = 0;
 698                 end   = dev->db_tab->max_group1;
 699                 dir   = 1;
 700                 break;
 701
 702         case MTHCA_DB_TYPE_CQ_SET_CI:
 703         case MTHCA_DB_TYPE_RQ:
 704         case MTHCA_DB_TYPE_SRQ:
 705                 group = 1;
 706                 start = dev->db_tab->npages - 1;
 707                 end   = dev->db_tab->min_group2;
 708                 dir   = -1;
 709                 break;
 710
 711         default:
 712                 ret = -EINVAL;
 713                 goto out;
 714         }
 715
 716         for (i = start; i != end; i += dir)
 717                 if (dev->db_tab->page[i].db_rec &&
 718                     !bitmap_full(dev->db_tab->page[i].used,
 719                                  MTHCA_DB_REC_PER_PAGE)) {
 720                         page = dev->db_tab->page + i;
 721                         goto found;
 722                 }
 723
 724         for (i = start; i != end; i += dir)
 725                 if (!dev->db_tab->page[i].db_rec) {
 726                         page = dev->db_tab->page + i;
 727                         goto alloc;
 728                 }
 729
 730         if (dev->db_tab->max_group1 >= dev->db_tab->min_group2 - 1) {
 731                 ret = -ENOMEM;
 732                 goto out;
 733         }
 734
 735         if (group == 0)
 736                 ++dev->db_tab->max_group1;
 737         else
 738                 --dev->db_tab->min_group2;
 739
 740         page = dev->db_tab->page + end;
 741
 742 alloc:
 743         page->db_rec = dma_alloc_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 744                                           &page->mapping, GFP_KERNEL);
 745         if (!page->db_rec) {
 746                 ret = -ENOMEM;
 747                 goto out;
 748         }
 749         memset(page->db_rec, 0, MTHCA_ICM_PAGE_SIZE);
 750
 751         ret = mthca_MAP_ICM_page(dev, page->mapping,
 752                                  mthca_uarc_virt(dev, &dev->driver_uar, i), &status);
 753         if (!ret && status)
 754                 ret = -EINVAL;
 755         if (ret) {
 756                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 757                                   page->db_rec, page->mapping);
 758                 goto out;
 759         }
 760
 761         bitmap_zero(page->used, MTHCA_DB_REC_PER_PAGE);
 762
 763 found:
 764         j = find_first_zero_bit(page->used, MTHCA_DB_REC_PER_PAGE);
 765         set_bit(j, page->used);
 766
 767         if (group == 1)
 768                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 769
 770         ret = i * MTHCA_DB_REC_PER_PAGE + j;
 771
 772         page->db_rec[j] = cpu_to_be64((qn << 8) | (type << 5));
 773
 774         *db = (__be32 *) &page->db_rec[j];
 775
 776 out:
 777         mutex_unlock(&dev->db_tab->mutex);
 778
 779         return ret;
 780 }
 781
 782 void mthca_free_db(struct mthca_dev *dev, int type, int db_index)
 783 {
 784         int i, j;
 785         struct mthca_db_page *page;
 786         u8 status;
 787
 788         i = db_index / MTHCA_DB_REC_PER_PAGE;
 789         j = db_index % MTHCA_DB_REC_PER_PAGE;
 790
 791         page = dev->db_tab->page + i;
 792
 793         mutex_lock(&dev->db_tab->mutex);
 794
 795         page->db_rec[j] = 0;
 796         if (i >= dev->db_tab->min_group2)
 797                 j = MTHCA_DB_REC_PER_PAGE - 1 - j;
 798         clear_bit(j, page->used);
 799
 800         if (bitmap_empty(page->used, MTHCA_DB_REC_PER_PAGE) &&
 801             i >= dev->db_tab->max_group1 - 1) {
 802                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 803
 804                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 805                                   page->db_rec, page->mapping);
 806                 page->db_rec = NULL;
 807
 808                 if (i == dev->db_tab->max_group1) {
 809                         --dev->db_tab->max_group1;
 810                         /* XXX may be able to unmap more pages now */
 811                 }
 812                 if (i == dev->db_tab->min_group2)
 813                         ++dev->db_tab->min_group2;
 814         }
 815
 816         mutex_unlock(&dev->db_tab->mutex);
 817 }
 818
 819 int mthca_init_db_tab(struct mthca_dev *dev)
 820 {
 821         int i;
 822
 823         if (!mthca_is_memfree(dev))
 824                 return 0;
 825
 826         dev->db_tab = kmalloc(sizeof *dev->db_tab, GFP_KERNEL);
 827         if (!dev->db_tab)
 828                 return -ENOMEM;
 829
 830         mutex_init(&dev->db_tab->mutex);
 831
 832         dev->db_tab->npages     = dev->uar_table.uarc_size / MTHCA_ICM_PAGE_SIZE;
 833         dev->db_tab->max_group1 = 0;
 834         dev->db_tab->min_group2 = dev->db_tab->npages - 1;
 835
 836         dev->db_tab->page = kmalloc(dev->db_tab->npages *
 837                                     sizeof *dev->db_tab->page,
 838                                     GFP_KERNEL);
 839         if (!dev->db_tab->page) {
 840                 kfree(dev->db_tab);
 841                 return -ENOMEM;
 842         }
 843
 844         for (i = 0; i < dev->db_tab->npages; ++i)
 845                 dev->db_tab->page[i].db_rec = NULL;
 846
 847         return 0;
 848 }
 849
 850 void mthca_cleanup_db_tab(struct mthca_dev *dev)
 851 {
 852         int i;
 853         u8 status;
 854
 855         if (!mthca_is_memfree(dev))
 856                 return;
 857
 858         /*
 859          * Because we don't always free our UARC pages when they
 860          * become empty to make mthca_free_db() simpler we need to
 861          * make a sweep through the doorbell pages and free any
 862          * leftover pages now.
 863          */
 864         for (i = 0; i < dev->db_tab->npages; ++i) {
 865                 if (!dev->db_tab->page[i].db_rec)
 866                         continue;
 867
 868                 if (!bitmap_empty(dev->db_tab->page[i].used, MTHCA_DB_REC_PER_PAGE))
 869                         mthca_warn(dev, "Kernel UARC page %d not empty\n", i);
 870
 871                 mthca_UNMAP_ICM(dev, mthca_uarc_virt(dev, &dev->driver_uar, i), 1, &status);
 872
 873                 dma_free_coherent(&dev->pdev->dev, MTHCA_ICM_PAGE_SIZE,
 874                                   dev->db_tab->page[i].db_rec,
 875                                   dev->db_tab->page[i].mapping);
 876         }
 877
 878         kfree(dev->db_tab->page);
 879         kfree(dev->db_tab);
 880 }