drivers/iommu/omap-iovmm.c

   1 /*
   2  * omap iommu: simple virtual address space management
   3  *
   4  * Copyright (C) 2008-2009 Nokia Corporation
   5  *
   6  * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/err.h>
  14 #include <linux/slab.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/device.h>
  17 #include <linux/scatterlist.h>
  18 #include <linux/iommu.h>
  19
  20 #include <asm/cacheflush.h>
  21 #include <asm/mach/map.h>
  22
  23 #include <plat/iommu.h>
  24 #include <plat/iovmm.h>
  25
  26 #include <plat/iopgtable.h>
  27
  28 static struct kmem_cache *iovm_area_cachep;
  29
  30 /* return the offset of the first scatterlist entry in a sg table */
  31 static unsigned int sgtable_offset(const struct sg_table *sgt)
  32 {
  33         if (!sgt || !sgt->nents)
  34                 return 0;
  35
  36         return sgt->sgl->offset;
  37 }
  38
  39 /* return total bytes of sg buffers */
  40 static size_t sgtable_len(const struct sg_table *sgt)
  41 {
  42         unsigned int i, total = 0;
  43         struct scatterlist *sg;
  44
  45         if (!sgt)
  46                 return 0;
  47
  48         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
  49                 size_t bytes;
  50
  51                 bytes = sg->length + sg->offset;
  52
  53                 if (!iopgsz_ok(bytes)) {
  54                         pr_err("%s: sg[%d] not iommu pagesize(%u %u)\n",
  55                                __func__, i, bytes, sg->offset);
  56                         return 0;
  57                 }
  58
  59                 if (i && sg->offset) {
  60                         pr_err("%s: sg[%d] offset not allowed in internal "
  61                                         "entries\n", __func__, i);
  62                         return 0;
  63                 }
  64
  65                 total += bytes;
  66         }
  67
  68         return total;
  69 }
  70 #define sgtable_ok(x)   (!!sgtable_len(x))
  71
  72 static unsigned max_alignment(u32 addr)
  73 {
  74         int i;
  75         unsigned pagesize[] = { SZ_16M, SZ_1M, SZ_64K, SZ_4K, };
  76         for (i = 0; i < ARRAY_SIZE(pagesize) && addr & (pagesize[i] - 1); i++)
  77                 ;
  78         return (i < ARRAY_SIZE(pagesize)) ? pagesize[i] : 0;
  79 }
  80
  81 /*
  82  * calculate the optimal number sg elements from total bytes based on
  83  * iommu superpages
  84  */
  85 static unsigned sgtable_nents(size_t bytes, u32 da, u32 pa)
  86 {
  87         unsigned nr_entries = 0, ent_sz;
  88
  89         if (!IS_ALIGNED(bytes, PAGE_SIZE)) {
  90                 pr_err("%s: wrong size %08x\n", __func__, bytes);
  91                 return 0;
  92         }
  93
  94         while (bytes) {
  95                 ent_sz = max_alignment(da | pa);
  96                 ent_sz = min_t(unsigned, ent_sz, iopgsz_max(bytes));
  97                 nr_entries++;
  98                 da += ent_sz;
  99                 pa += ent_sz;
 100                 bytes -= ent_sz;
 101         }
 102
 103         return nr_entries;
 104 }
 105
 106 /* allocate and initialize sg_table header(a kind of 'superblock') */
 107 static struct sg_table *sgtable_alloc(const size_t bytes, u32 flags,
 108                                                         u32 da, u32 pa)
 109 {
 110         unsigned int nr_entries;
 111         int err;
 112         struct sg_table *sgt;
 113
 114         if (!bytes)
 115                 return ERR_PTR(-EINVAL);
 116
 117         if (!IS_ALIGNED(bytes, PAGE_SIZE))
 118                 return ERR_PTR(-EINVAL);
 119
 120         if (flags & IOVMF_LINEAR) {
 121                 nr_entries = sgtable_nents(bytes, da, pa);
 122                 if (!nr_entries)
 123                         return ERR_PTR(-EINVAL);
 124         } else
 125                 nr_entries =  bytes / PAGE_SIZE;
 126
 127         sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 128         if (!sgt)
 129                 return ERR_PTR(-ENOMEM);
 130
 131         err = sg_alloc_table(sgt, nr_entries, GFP_KERNEL);
 132         if (err) {
 133                 kfree(sgt);
 134                 return ERR_PTR(err);
 135         }
 136
 137         pr_debug("%s: sgt:%p(%d entries)\n", __func__, sgt, nr_entries);
 138
 139         return sgt;
 140 }
 141
 142 /* free sg_table header(a kind of superblock) */
 143 static void sgtable_free(struct sg_table *sgt)
 144 {
 145         if (!sgt)
 146                 return;
 147
 148         sg_free_table(sgt);
 149         kfree(sgt);
 150
 151         pr_debug("%s: sgt:%p\n", __func__, sgt);
 152 }
 153
 154 /* map 'sglist' to a contiguous mpu virtual area and return 'va' */
 155 static void *vmap_sg(const struct sg_table *sgt)
 156 {
 157         u32 va;
 158         size_t total;
 159         unsigned int i;
 160         struct scatterlist *sg;
 161         struct vm_struct *new;
 162         const struct mem_type *mtype;
 163
 164         mtype = get_mem_type(MT_DEVICE);
 165         if (!mtype)
 166                 return ERR_PTR(-EINVAL);
 167
 168         total = sgtable_len(sgt);
 169         if (!total)
 170                 return ERR_PTR(-EINVAL);
 171
 172         new = __get_vm_area(total, VM_IOREMAP, VMALLOC_START, VMALLOC_END);
 173         if (!new)
 174                 return ERR_PTR(-ENOMEM);
 175         va = (u32)new->addr;
 176
 177         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 178                 size_t bytes;
 179                 u32 pa;
 180                 int err;
 181
 182                 pa = sg_phys(sg) - sg->offset;
 183                 bytes = sg->length + sg->offset;
 184
 185                 BUG_ON(bytes != PAGE_SIZE);
 186
 187                 err = ioremap_page(va,  pa, mtype);
 188                 if (err)
 189                         goto err_out;
 190
 191                 va += bytes;
 192         }
 193
 194         flush_cache_vmap((unsigned long)new->addr,
 195                                 (unsigned long)(new->addr + total));
 196         return new->addr;
 197
 198 err_out:
 199         WARN_ON(1); /* FIXME: cleanup some mpu mappings */
 200         vunmap(new->addr);
 201         return ERR_PTR(-EAGAIN);
 202 }
 203
 204 static inline void vunmap_sg(const void *va)
 205 {
 206         vunmap(va);
 207 }
 208
 209 static struct iovm_struct *__find_iovm_area(struct omap_iommu *obj,
 210                                                         const u32 da)
 211 {
 212         struct iovm_struct *tmp;
 213
 214         list_for_each_entry(tmp, &obj->mmap, list) {
 215                 if ((da >= tmp->da_start) && (da < tmp->da_end)) {
 216                         size_t len;
 217
 218                         len = tmp->da_end - tmp->da_start;
 219
 220                         dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n",
 221                                 __func__, tmp->da_start, da, tmp->da_end, len,
 222                                 tmp->flags);
 223
 224                         return tmp;
 225                 }
 226         }
 227
 228         return NULL;
 229 }
 230
 231 /**
 232  * omap_find_iovm_area  -  find iovma which includes @da
 233  * @da:         iommu device virtual address
 234  *
 235  * Find the existing iovma starting at @da
 236  */
 237 struct iovm_struct *omap_find_iovm_area(struct omap_iommu *obj, u32 da)
 238 {
 239         struct iovm_struct *area;
 240
 241         mutex_lock(&obj->mmap_lock);
 242         area = __find_iovm_area(obj, da);
 243         mutex_unlock(&obj->mmap_lock);
 244
 245         return area;
 246 }
 247 EXPORT_SYMBOL_GPL(omap_find_iovm_area);
 248
 249 /*
 250  * This finds the hole(area) which fits the requested address and len
 251  * in iovmas mmap, and returns the new allocated iovma.
 252  */
 253 static struct iovm_struct *alloc_iovm_area(struct omap_iommu *obj, u32 da,
 254                                            size_t bytes, u32 flags)
 255 {
 256         struct iovm_struct *new, *tmp;
 257         u32 start, prev_end, alignment;
 258
 259         if (!obj || !bytes)
 260                 return ERR_PTR(-EINVAL);
 261
 262         start = da;
 263         alignment = PAGE_SIZE;
 264
 265         if (~flags & IOVMF_DA_FIXED) {
 266                 /* Don't map address 0 */
 267                 start = obj->da_start ? obj->da_start : alignment;
 268
 269                 if (flags & IOVMF_LINEAR)
 270                         alignment = iopgsz_max(bytes);
 271                 start = roundup(start, alignment);
 272         } else if (start < obj->da_start || start > obj->da_end ||
 273                                         obj->da_end - start < bytes) {
 274                 return ERR_PTR(-EINVAL);
 275         }
 276
 277         tmp = NULL;
 278         if (list_empty(&obj->mmap))
 279                 goto found;
 280
 281         prev_end = 0;
 282         list_for_each_entry(tmp, &obj->mmap, list) {
 283
 284                 if (prev_end > start)
 285                         break;
 286
 287                 if (tmp->da_start > start && (tmp->da_start - start) >= bytes)
 288                         goto found;
 289
 290                 if (tmp->da_end >= start && ~flags & IOVMF_DA_FIXED)
 291                         start = roundup(tmp->da_end + 1, alignment);
 292
 293                 prev_end = tmp->da_end;
 294         }
 295
 296         if ((start >= prev_end) && (obj->da_end - start >= bytes))
 297                 goto found;
 298
 299         dev_dbg(obj->dev, "%s: no space to fit %08x(%x) flags: %08x\n",
 300                 __func__, da, bytes, flags);
 301
 302         return ERR_PTR(-EINVAL);
 303
 304 found:
 305         new = kmem_cache_zalloc(iovm_area_cachep, GFP_KERNEL);
 306         if (!new)
 307                 return ERR_PTR(-ENOMEM);
 308
 309         new->iommu = obj;
 310         new->da_start = start;
 311         new->da_end = start + bytes;
 312         new->flags = flags;
 313
 314         /*
 315          * keep ascending order of iovmas
 316          */
 317         if (tmp)
 318                 list_add_tail(&new->list, &tmp->list);
 319         else
 320                 list_add(&new->list, &obj->mmap);
 321
 322         dev_dbg(obj->dev, "%s: found %08x-%08x-%08x(%x) %08x\n",
 323                 __func__, new->da_start, start, new->da_end, bytes, flags);
 324
 325         return new;
 326 }
 327
 328 static void free_iovm_area(struct omap_iommu *obj, struct iovm_struct *area)
 329 {
 330         size_t bytes;
 331
 332         BUG_ON(!obj || !area);
 333
 334         bytes = area->da_end - area->da_start;
 335
 336         dev_dbg(obj->dev, "%s: %08x-%08x(%x) %08x\n",
 337                 __func__, area->da_start, area->da_end, bytes, area->flags);
 338
 339         list_del(&area->list);
 340         kmem_cache_free(iovm_area_cachep, area);
 341 }
 342
 343 /**
 344  * omap_da_to_va - convert (d) to (v)
 345  * @obj:        objective iommu
 346  * @da:         iommu device virtual address
 347  * @va:         mpu virtual address
 348  *
 349  * Returns mpu virtual addr which corresponds to a given device virtual addr
 350  */
 351 void *omap_da_to_va(struct omap_iommu *obj, u32 da)
 352 {
 353         void *va = NULL;
 354         struct iovm_struct *area;
 355
 356         mutex_lock(&obj->mmap_lock);
 357
 358         area = __find_iovm_area(obj, da);
 359         if (!area) {
 360                 dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
 361                 goto out;
 362         }
 363         va = area->va;
 364 out:
 365         mutex_unlock(&obj->mmap_lock);
 366
 367         return va;
 368 }
 369 EXPORT_SYMBOL_GPL(omap_da_to_va);
 370
 371 static void sgtable_fill_vmalloc(struct sg_table *sgt, void *_va)
 372 {
 373         unsigned int i;
 374         struct scatterlist *sg;
 375         void *va = _va;
 376         void *va_end;
 377
 378         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 379                 struct page *pg;
 380                 const size_t bytes = PAGE_SIZE;
 381
 382                 /*
 383                  * iommu 'superpage' isn't supported with 'omap_iommu_vmalloc()'
 384                  */
 385                 pg = vmalloc_to_page(va);
 386                 BUG_ON(!pg);
 387                 sg_set_page(sg, pg, bytes, 0);
 388
 389                 va += bytes;
 390         }
 391
 392         va_end = _va + PAGE_SIZE * i;
 393 }
 394
 395 static inline void sgtable_drain_vmalloc(struct sg_table *sgt)
 396 {
 397         /*
 398          * Actually this is not necessary at all, just exists for
 399          * consistency of the code readability.
 400          */
 401         BUG_ON(!sgt);
 402 }
 403
 404 /* create 'da' <-> 'pa' mapping from 'sgt' */
 405 static int map_iovm_area(struct iommu_domain *domain, struct iovm_struct *new,
 406                         const struct sg_table *sgt, u32 flags)
 407 {
 408         int err;
 409         unsigned int i, j;
 410         struct scatterlist *sg;
 411         u32 da = new->da_start;
 412         int order;
 413
 414         if (!domain || !sgt)
 415                 return -EINVAL;
 416
 417         BUG_ON(!sgtable_ok(sgt));
 418
 419         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 420                 u32 pa;
 421                 size_t bytes;
 422
 423                 pa = sg_phys(sg) - sg->offset;
 424                 bytes = sg->length + sg->offset;
 425
 426                 flags &= ~IOVMF_PGSZ_MASK;
 427
 428                 if (bytes_to_iopgsz(bytes) < 0)
 429                         goto err_out;
 430
 431                 order = get_order(bytes);
 432
 433                 pr_debug("%s: [%d] %08x %08x(%x)\n", __func__,
 434                          i, da, pa, bytes);
 435
 436                 err = iommu_map(domain, da, pa, order, flags);
 437                 if (err)
 438                         goto err_out;
 439
 440                 da += bytes;
 441         }
 442         return 0;
 443
 444 err_out:
 445         da = new->da_start;
 446
 447         for_each_sg(sgt->sgl, sg, i, j) {
 448                 size_t bytes;
 449
 450                 bytes = sg->length + sg->offset;
 451                 order = get_order(bytes);
 452
 453                 /* ignore failures.. we're already handling one */
 454                 iommu_unmap(domain, da, order);
 455
 456                 da += bytes;
 457         }
 458         return err;
 459 }
 460
 461 /* release 'da' <-> 'pa' mapping */
 462 static void unmap_iovm_area(struct iommu_domain *domain, struct omap_iommu *obj,
 463                                                 struct iovm_struct *area)
 464 {
 465         u32 start;
 466         size_t total = area->da_end - area->da_start;
 467         const struct sg_table *sgt = area->sgt;
 468         struct scatterlist *sg;
 469         int i, err;
 470
 471         BUG_ON(!sgtable_ok(sgt));
 472         BUG_ON((!total) || !IS_ALIGNED(total, PAGE_SIZE));
 473
 474         start = area->da_start;
 475         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 476                 size_t bytes;
 477                 int order;
 478
 479                 bytes = sg->length + sg->offset;
 480                 order = get_order(bytes);
 481
 482                 err = iommu_unmap(domain, start, order);
 483                 if (err < 0)
 484                         break;
 485
 486                 dev_dbg(obj->dev, "%s: unmap %08x(%x) %08x\n",
 487                                 __func__, start, bytes, area->flags);
 488
 489                 BUG_ON(!IS_ALIGNED(bytes, PAGE_SIZE));
 490
 491                 total -= bytes;
 492                 start += bytes;
 493         }
 494         BUG_ON(total);
 495 }
 496
 497 /* template function for all unmapping */
 498 static struct sg_table *unmap_vm_area(struct iommu_domain *domain,
 499                                       struct omap_iommu *obj, const u32 da,
 500                                       void (*fn)(const void *), u32 flags)
 501 {
 502         struct sg_table *sgt = NULL;
 503         struct iovm_struct *area;
 504
 505         if (!IS_ALIGNED(da, PAGE_SIZE)) {
 506                 dev_err(obj->dev, "%s: alignment err(%08x)\n", __func__, da);
 507                 return NULL;
 508         }
 509
 510         mutex_lock(&obj->mmap_lock);
 511
 512         area = __find_iovm_area(obj, da);
 513         if (!area) {
 514                 dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
 515                 goto out;
 516         }
 517
 518         if ((area->flags & flags) != flags) {
 519                 dev_err(obj->dev, "%s: wrong flags(%08x)\n", __func__,
 520                         area->flags);
 521                 goto out;
 522         }
 523         sgt = (struct sg_table *)area->sgt;
 524
 525         unmap_iovm_area(domain, obj, area);
 526
 527         fn(area->va);
 528
 529         dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n", __func__,
 530                 area->da_start, da, area->da_end,
 531                 area->da_end - area->da_start, area->flags);
 532
 533         free_iovm_area(obj, area);
 534 out:
 535         mutex_unlock(&obj->mmap_lock);
 536
 537         return sgt;
 538 }
 539
 540 static u32 map_iommu_region(struct iommu_domain *domain, struct omap_iommu *obj,
 541                                 u32 da, const struct sg_table *sgt, void *va,
 542                                 size_t bytes, u32 flags)
 543 {
 544         int err = -ENOMEM;
 545         struct iovm_struct *new;
 546
 547         mutex_lock(&obj->mmap_lock);
 548
 549         new = alloc_iovm_area(obj, da, bytes, flags);
 550         if (IS_ERR(new)) {
 551                 err = PTR_ERR(new);
 552                 goto err_alloc_iovma;
 553         }
 554         new->va = va;
 555         new->sgt = sgt;
 556
 557         if (map_iovm_area(domain, new, sgt, new->flags))
 558                 goto err_map;
 559
 560         mutex_unlock(&obj->mmap_lock);
 561
 562         dev_dbg(obj->dev, "%s: da:%08x(%x) flags:%08x va:%p\n",
 563                 __func__, new->da_start, bytes, new->flags, va);
 564
 565         return new->da_start;
 566
 567 err_map:
 568         free_iovm_area(obj, new);
 569 err_alloc_iovma:
 570         mutex_unlock(&obj->mmap_lock);
 571         return err;
 572 }
 573
 574 static inline u32
 575 __iommu_vmap(struct iommu_domain *domain, struct omap_iommu *obj,
 576                                 u32 da, const struct sg_table *sgt,
 577                                 void *va, size_t bytes, u32 flags)
 578 {
 579         return map_iommu_region(domain, obj, da, sgt, va, bytes, flags);
 580 }
 581
 582 /**
 583  * omap_iommu_vmap  -  (d)-(p)-(v) address mapper
 584  * @obj:        objective iommu
 585  * @sgt:        address of scatter gather table
 586  * @flags:      iovma and page property
 587  *
 588  * Creates 1-n-1 mapping with given @sgt and returns @da.
 589  * All @sgt element must be io page size aligned.
 590  */
 591 u32 omap_iommu_vmap(struct iommu_domain *domain, struct omap_iommu *obj, u32 da,
 592                 const struct sg_table *sgt, u32 flags)
 593 {
 594         size_t bytes;
 595         void *va = NULL;
 596
 597         if (!obj || !obj->dev || !sgt)
 598                 return -EINVAL;
 599
 600         bytes = sgtable_len(sgt);
 601         if (!bytes)
 602                 return -EINVAL;
 603         bytes = PAGE_ALIGN(bytes);
 604
 605         if (flags & IOVMF_MMIO) {
 606                 va = vmap_sg(sgt);
 607                 if (IS_ERR(va))
 608                         return PTR_ERR(va);
 609         }
 610
 611         flags |= IOVMF_DISCONT;
 612         flags |= IOVMF_MMIO;
 613
 614         da = __iommu_vmap(domain, obj, da, sgt, va, bytes, flags);
 615         if (IS_ERR_VALUE(da))
 616                 vunmap_sg(va);
 617
 618         return da + sgtable_offset(sgt);
 619 }
 620 EXPORT_SYMBOL_GPL(omap_iommu_vmap);
 621
 622 /**
 623  * omap_iommu_vunmap  -  release virtual mapping obtained by 'omap_iommu_vmap()'
 624  * @obj:        objective iommu
 625  * @da:         iommu device virtual address
 626  *
 627  * Free the iommu virtually contiguous memory area starting at
 628  * @da, which was returned by 'omap_iommu_vmap()'.
 629  */
 630 struct sg_table *
 631 omap_iommu_vunmap(struct iommu_domain *domain, struct omap_iommu *obj, u32 da)
 632 {
 633         struct sg_table *sgt;
 634         /*
 635          * 'sgt' is allocated before 'omap_iommu_vmalloc()' is called.
 636          * Just returns 'sgt' to the caller to free
 637          */
 638         da &= PAGE_MASK;
 639         sgt = unmap_vm_area(domain, obj, da, vunmap_sg,
 640                                         IOVMF_DISCONT | IOVMF_MMIO);
 641         if (!sgt)
 642                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 643         return sgt;
 644 }
 645 EXPORT_SYMBOL_GPL(omap_iommu_vunmap);
 646
 647 /**
 648  * omap_iommu_vmalloc  -  (d)-(p)-(v) address allocator and mapper
 649  * @obj:        objective iommu
 650  * @da:         contiguous iommu virtual memory
 651  * @bytes:      allocation size
 652  * @flags:      iovma and page property
 653  *
 654  * Allocate @bytes linearly and creates 1-n-1 mapping and returns
 655  * @da again, which might be adjusted if 'IOVMF_DA_FIXED' is not set.
 656  */
 657 u32
 658 omap_iommu_vmalloc(struct iommu_domain *domain, struct omap_iommu *obj, u32 da,
 659                                                 size_t bytes, u32 flags)
 660 {
 661         void *va;
 662         struct sg_table *sgt;
 663
 664         if (!obj || !obj->dev || !bytes)
 665                 return -EINVAL;
 666
 667         bytes = PAGE_ALIGN(bytes);
 668
 669         va = vmalloc(bytes);
 670         if (!va)
 671                 return -ENOMEM;
 672
 673         flags |= IOVMF_DISCONT;
 674         flags |= IOVMF_ALLOC;
 675
 676         sgt = sgtable_alloc(bytes, flags, da, 0);
 677         if (IS_ERR(sgt)) {
 678                 da = PTR_ERR(sgt);
 679                 goto err_sgt_alloc;
 680         }
 681         sgtable_fill_vmalloc(sgt, va);
 682
 683         da = __iommu_vmap(domain, obj, da, sgt, va, bytes, flags);
 684         if (IS_ERR_VALUE(da))
 685                 goto err_iommu_vmap;
 686
 687         return da;
 688
 689 err_iommu_vmap:
 690         sgtable_drain_vmalloc(sgt);
 691         sgtable_free(sgt);
 692 err_sgt_alloc:
 693         vfree(va);
 694         return da;
 695 }
 696 EXPORT_SYMBOL_GPL(omap_iommu_vmalloc);
 697
 698 /**
 699  * omap_iommu_vfree  -  release memory allocated by 'omap_iommu_vmalloc()'
 700  * @obj:        objective iommu
 701  * @da:         iommu device virtual address
 702  *
 703  * Frees the iommu virtually continuous memory area starting at
 704  * @da, as obtained from 'omap_iommu_vmalloc()'.
 705  */
 706 void omap_iommu_vfree(struct iommu_domain *domain, struct omap_iommu *obj,
 707                                                                 const u32 da)
 708 {
 709         struct sg_table *sgt;
 710
 711         sgt = unmap_vm_area(domain, obj, da, vfree,
 712                                                 IOVMF_DISCONT | IOVMF_ALLOC);
 713         if (!sgt)
 714                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 715         sgtable_free(sgt);
 716 }
 717 EXPORT_SYMBOL_GPL(omap_iommu_vfree);
 718
 719 static int __init iovmm_init(void)
 720 {
 721         const unsigned long flags = SLAB_HWCACHE_ALIGN;
 722         struct kmem_cache *p;
 723
 724         p = kmem_cache_create("iovm_area_cache", sizeof(struct iovm_struct), 0,
 725                               flags, NULL);
 726         if (!p)
 727                 return -ENOMEM;
 728         iovm_area_cachep = p;
 729
 730         return 0;
 731 }
 732 module_init(iovmm_init);
 733
 734 static void __exit iovmm_exit(void)
 735 {
 736         kmem_cache_destroy(iovm_area_cachep);
 737 }
 738 module_exit(iovmm_exit);
 739
 740 MODULE_DESCRIPTION("omap iommu: simple virtual address space management");
 741 MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
 742 MODULE_LICENSE("GPL v2");