arch/arm/plat-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
  19 #include <asm/cacheflush.h>
  20 #include <asm/mach/map.h>
  21
  22 #include <plat/iommu.h>
  23 #include <plat/iovmm.h>
  24
  25 #include "iopgtable.h"
  26
  27 /*
  28  * A device driver needs to create address mappings between:
  29  *
  30  * - iommu/device address
  31  * - physical address
  32  * - mpu virtual address
  33  *
  34  * There are 4 possible patterns for them:
  35  *
  36  *    |iova/                      mapping               iommu_          page
  37  *    | da      pa      va      (d)-(p)-(v)             function        type
  38  *  ---------------------------------------------------------------------------
  39  *  1 | c       c       c        1 - 1 - 1        _kmap() / _kunmap()   s
  40  *  2 | c       c,a     c        1 - 1 - 1      _kmalloc()/ _kfree()    s
  41  *  3 | c       d       c        1 - n - 1        _vmap() / _vunmap()   s
  42  *  4 | c       d,a     c        1 - n - 1      _vmalloc()/ _vfree()    n*
  43  *
  44  *
  45  *      'iova': device iommu virtual address
  46  *      'da':   alias of 'iova'
  47  *      'pa':   physical address
  48  *      'va':   mpu virtual address
  49  *
  50  *      'c':    contiguous memory area
  51  *      'd':    discontiguous memory area
  52  *      'a':    anonymous memory allocation
  53  *      '()':   optional feature
  54  *
  55  *      'n':    a normal page(4KB) size is used.
  56  *      's':    multiple iommu superpage(16MB, 1MB, 64KB, 4KB) size is used.
  57  *
  58  *      '*':    not yet, but feasible.
  59  */
  60
  61 static struct kmem_cache *iovm_area_cachep;
  62
  63 /* return total bytes of sg buffers */
  64 static size_t sgtable_len(const struct sg_table *sgt)
  65 {
  66         unsigned int i, total = 0;
  67         struct scatterlist *sg;
  68
  69         if (!sgt)
  70                 return 0;
  71
  72         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
  73                 size_t bytes;
  74
  75                 bytes = sg_dma_len(sg);
  76
  77                 if (!iopgsz_ok(bytes)) {
  78                         pr_err("%s: sg[%d] not iommu pagesize(%x)\n",
  79                                __func__, i, bytes);
  80                         return 0;
  81                 }
  82
  83                 total += bytes;
  84         }
  85
  86         return total;
  87 }
  88 #define sgtable_ok(x)   (!!sgtable_len(x))
  89
  90 static unsigned max_alignment(u32 addr)
  91 {
  92         int i;
  93         unsigned pagesize[] = { SZ_16M, SZ_1M, SZ_64K, SZ_4K, };
  94         for (i = 0; i < ARRAY_SIZE(pagesize) && addr & (pagesize[i] - 1); i++)
  95                 ;
  96         return (i < ARRAY_SIZE(pagesize)) ? pagesize[i] : 0;
  97 }
  98
  99 /*
 100  * calculate the optimal number sg elements from total bytes based on
 101  * iommu superpages
 102  */
 103 static unsigned sgtable_nents(size_t bytes, u32 da, u32 pa)
 104 {
 105         unsigned nr_entries = 0, ent_sz;
 106
 107         if (!IS_ALIGNED(bytes, PAGE_SIZE)) {
 108                 pr_err("%s: wrong size %08x\n", __func__, bytes);
 109                 return 0;
 110         }
 111
 112         while (bytes) {
 113                 ent_sz = max_alignment(da | pa);
 114                 ent_sz = min_t(unsigned, ent_sz, iopgsz_max(bytes));
 115                 nr_entries++;
 116                 da += ent_sz;
 117                 pa += ent_sz;
 118                 bytes -= ent_sz;
 119         }
 120
 121         return nr_entries;
 122 }
 123
 124 /* allocate and initialize sg_table header(a kind of 'superblock') */
 125 static struct sg_table *sgtable_alloc(const size_t bytes, u32 flags,
 126                                                         u32 da, u32 pa)
 127 {
 128         unsigned int nr_entries;
 129         int err;
 130         struct sg_table *sgt;
 131
 132         if (!bytes)
 133                 return ERR_PTR(-EINVAL);
 134
 135         if (!IS_ALIGNED(bytes, PAGE_SIZE))
 136                 return ERR_PTR(-EINVAL);
 137
 138         if (flags & IOVMF_LINEAR) {
 139                 nr_entries = sgtable_nents(bytes, da, pa);
 140                 if (!nr_entries)
 141                         return ERR_PTR(-EINVAL);
 142         } else
 143                 nr_entries =  bytes / PAGE_SIZE;
 144
 145         sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 146         if (!sgt)
 147                 return ERR_PTR(-ENOMEM);
 148
 149         err = sg_alloc_table(sgt, nr_entries, GFP_KERNEL);
 150         if (err) {
 151                 kfree(sgt);
 152                 return ERR_PTR(err);
 153         }
 154
 155         pr_debug("%s: sgt:%p(%d entries)\n", __func__, sgt, nr_entries);
 156
 157         return sgt;
 158 }
 159
 160 /* free sg_table header(a kind of superblock) */
 161 static void sgtable_free(struct sg_table *sgt)
 162 {
 163         if (!sgt)
 164                 return;
 165
 166         sg_free_table(sgt);
 167         kfree(sgt);
 168
 169         pr_debug("%s: sgt:%p\n", __func__, sgt);
 170 }
 171
 172 /* map 'sglist' to a contiguous mpu virtual area and return 'va' */
 173 static void *vmap_sg(const struct sg_table *sgt)
 174 {
 175         u32 va;
 176         size_t total;
 177         unsigned int i;
 178         struct scatterlist *sg;
 179         struct vm_struct *new;
 180         const struct mem_type *mtype;
 181
 182         mtype = get_mem_type(MT_DEVICE);
 183         if (!mtype)
 184                 return ERR_PTR(-EINVAL);
 185
 186         total = sgtable_len(sgt);
 187         if (!total)
 188                 return ERR_PTR(-EINVAL);
 189
 190         new = __get_vm_area(total, VM_IOREMAP, VMALLOC_START, VMALLOC_END);
 191         if (!new)
 192                 return ERR_PTR(-ENOMEM);
 193         va = (u32)new->addr;
 194
 195         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 196                 size_t bytes;
 197                 u32 pa;
 198                 int err;
 199
 200                 pa = sg_phys(sg);
 201                 bytes = sg_dma_len(sg);
 202
 203                 BUG_ON(bytes != PAGE_SIZE);
 204
 205                 err = ioremap_page(va,  pa, mtype);
 206                 if (err)
 207                         goto err_out;
 208
 209                 va += bytes;
 210         }
 211
 212         flush_cache_vmap((unsigned long)new->addr,
 213                                 (unsigned long)(new->addr + total));
 214         return new->addr;
 215
 216 err_out:
 217         WARN_ON(1); /* FIXME: cleanup some mpu mappings */
 218         vunmap(new->addr);
 219         return ERR_PTR(-EAGAIN);
 220 }
 221
 222 static inline void vunmap_sg(const void *va)
 223 {
 224         vunmap(va);
 225 }
 226
 227 static struct iovm_struct *__find_iovm_area(struct iommu *obj, const u32 da)
 228 {
 229         struct iovm_struct *tmp;
 230
 231         list_for_each_entry(tmp, &obj->mmap, list) {
 232                 if ((da >= tmp->da_start) && (da < tmp->da_end)) {
 233                         size_t len;
 234
 235                         len = tmp->da_end - tmp->da_start;
 236
 237                         dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n",
 238                                 __func__, tmp->da_start, da, tmp->da_end, len,
 239                                 tmp->flags);
 240
 241                         return tmp;
 242                 }
 243         }
 244
 245         return NULL;
 246 }
 247
 248 /**
 249  * find_iovm_area  -  find iovma which includes @da
 250  * @da:         iommu device virtual address
 251  *
 252  * Find the existing iovma starting at @da
 253  */
 254 struct iovm_struct *find_iovm_area(struct iommu *obj, u32 da)
 255 {
 256         struct iovm_struct *area;
 257
 258         mutex_lock(&obj->mmap_lock);
 259         area = __find_iovm_area(obj, da);
 260         mutex_unlock(&obj->mmap_lock);
 261
 262         return area;
 263 }
 264 EXPORT_SYMBOL_GPL(find_iovm_area);
 265
 266 /*
 267  * This finds the hole(area) which fits the requested address and len
 268  * in iovmas mmap, and returns the new allocated iovma.
 269  */
 270 static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
 271                                            size_t bytes, u32 flags)
 272 {
 273         struct iovm_struct *new, *tmp;
 274         u32 start, prev_end, alignment;
 275
 276         if (!obj || !bytes)
 277                 return ERR_PTR(-EINVAL);
 278
 279         start = da;
 280         alignment = PAGE_SIZE;
 281
 282         if (~flags & IOVMF_DA_FIXED) {
 283                 /* Don't map address 0 */
 284                 start = obj->da_start ? obj->da_start : alignment;
 285
 286                 if (flags & IOVMF_LINEAR)
 287                         alignment = iopgsz_max(bytes);
 288                 start = roundup(start, alignment);
 289         } else if (start < obj->da_start || start > obj->da_end ||
 290                                         obj->da_end - start < bytes) {
 291                 return ERR_PTR(-EINVAL);
 292         }
 293
 294         tmp = NULL;
 295         if (list_empty(&obj->mmap))
 296                 goto found;
 297
 298         prev_end = 0;
 299         list_for_each_entry(tmp, &obj->mmap, list) {
 300
 301                 if (prev_end > start)
 302                         break;
 303
 304                 if (tmp->da_start > start && (tmp->da_start - start) >= bytes)
 305                         goto found;
 306
 307                 if (tmp->da_end >= start && ~flags & IOVMF_DA_FIXED)
 308                         start = roundup(tmp->da_end + 1, alignment);
 309
 310                 prev_end = tmp->da_end;
 311         }
 312
 313         if ((start >= prev_end) && (obj->da_end - start >= bytes))
 314                 goto found;
 315
 316         dev_dbg(obj->dev, "%s: no space to fit %08x(%x) flags: %08x\n",
 317                 __func__, da, bytes, flags);
 318
 319         return ERR_PTR(-EINVAL);
 320
 321 found:
 322         new = kmem_cache_zalloc(iovm_area_cachep, GFP_KERNEL);
 323         if (!new)
 324                 return ERR_PTR(-ENOMEM);
 325
 326         new->iommu = obj;
 327         new->da_start = start;
 328         new->da_end = start + bytes;
 329         new->flags = flags;
 330
 331         /*
 332          * keep ascending order of iovmas
 333          */
 334         if (tmp)
 335                 list_add_tail(&new->list, &tmp->list);
 336         else
 337                 list_add(&new->list, &obj->mmap);
 338
 339         dev_dbg(obj->dev, "%s: found %08x-%08x-%08x(%x) %08x\n",
 340                 __func__, new->da_start, start, new->da_end, bytes, flags);
 341
 342         return new;
 343 }
 344
 345 static void free_iovm_area(struct iommu *obj, struct iovm_struct *area)
 346 {
 347         size_t bytes;
 348
 349         BUG_ON(!obj || !area);
 350
 351         bytes = area->da_end - area->da_start;
 352
 353         dev_dbg(obj->dev, "%s: %08x-%08x(%x) %08x\n",
 354                 __func__, area->da_start, area->da_end, bytes, area->flags);
 355
 356         list_del(&area->list);
 357         kmem_cache_free(iovm_area_cachep, area);
 358 }
 359
 360 /**
 361  * da_to_va - convert (d) to (v)
 362  * @obj:        objective iommu
 363  * @da:         iommu device virtual address
 364  * @va:         mpu virtual address
 365  *
 366  * Returns mpu virtual addr which corresponds to a given device virtual addr
 367  */
 368 void *da_to_va(struct iommu *obj, u32 da)
 369 {
 370         void *va = NULL;
 371         struct iovm_struct *area;
 372
 373         mutex_lock(&obj->mmap_lock);
 374
 375         area = __find_iovm_area(obj, da);
 376         if (!area) {
 377                 dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
 378                 goto out;
 379         }
 380         va = area->va;
 381 out:
 382         mutex_unlock(&obj->mmap_lock);
 383
 384         return va;
 385 }
 386 EXPORT_SYMBOL_GPL(da_to_va);
 387
 388 static void sgtable_fill_vmalloc(struct sg_table *sgt, void *_va)
 389 {
 390         unsigned int i;
 391         struct scatterlist *sg;
 392         void *va = _va;
 393         void *va_end;
 394
 395         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 396                 struct page *pg;
 397                 const size_t bytes = PAGE_SIZE;
 398
 399                 /*
 400                  * iommu 'superpage' isn't supported with 'iommu_vmalloc()'
 401                  */
 402                 pg = vmalloc_to_page(va);
 403                 BUG_ON(!pg);
 404                 sg_set_page(sg, pg, bytes, 0);
 405
 406                 va += bytes;
 407         }
 408
 409         va_end = _va + PAGE_SIZE * i;
 410 }
 411
 412 static inline void sgtable_drain_vmalloc(struct sg_table *sgt)
 413 {
 414         /*
 415          * Actually this is not necessary at all, just exists for
 416          * consistency of the code readability.
 417          */
 418         BUG_ON(!sgt);
 419 }
 420
 421 static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, u32 da,
 422                                                                 size_t len)
 423 {
 424         unsigned int i;
 425         struct scatterlist *sg;
 426         void *va;
 427
 428         va = phys_to_virt(pa);
 429
 430         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 431                 unsigned bytes;
 432
 433                 bytes = max_alignment(da | pa);
 434                 bytes = min_t(unsigned, bytes, iopgsz_max(len));
 435
 436                 BUG_ON(!iopgsz_ok(bytes));
 437
 438                 sg_set_buf(sg, phys_to_virt(pa), bytes);
 439                 /*
 440                  * 'pa' is cotinuous(linear).
 441                  */
 442                 pa += bytes;
 443                 da += bytes;
 444                 len -= bytes;
 445         }
 446         BUG_ON(len);
 447 }
 448
 449 static inline void sgtable_drain_kmalloc(struct sg_table *sgt)
 450 {
 451         /*
 452          * Actually this is not necessary at all, just exists for
 453          * consistency of the code readability
 454          */
 455         BUG_ON(!sgt);
 456 }
 457
 458 /* create 'da' <-> 'pa' mapping from 'sgt' */
 459 static int map_iovm_area(struct iommu *obj, struct iovm_struct *new,
 460                          const struct sg_table *sgt, u32 flags)
 461 {
 462         int err;
 463         unsigned int i, j;
 464         struct scatterlist *sg;
 465         u32 da = new->da_start;
 466
 467         if (!obj || !sgt)
 468                 return -EINVAL;
 469
 470         BUG_ON(!sgtable_ok(sgt));
 471
 472         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 473                 u32 pa;
 474                 int pgsz;
 475                 size_t bytes;
 476                 struct iotlb_entry e;
 477
 478                 pa = sg_phys(sg);
 479                 bytes = sg_dma_len(sg);
 480
 481                 flags &= ~IOVMF_PGSZ_MASK;
 482                 pgsz = bytes_to_iopgsz(bytes);
 483                 if (pgsz < 0)
 484                         goto err_out;
 485                 flags |= pgsz;
 486
 487                 pr_debug("%s: [%d] %08x %08x(%x)\n", __func__,
 488                          i, da, pa, bytes);
 489
 490                 iotlb_init_entry(&e, da, pa, flags);
 491                 err = iopgtable_store_entry(obj, &e);
 492                 if (err)
 493                         goto err_out;
 494
 495                 da += bytes;
 496         }
 497         return 0;
 498
 499 err_out:
 500         da = new->da_start;
 501
 502         for_each_sg(sgt->sgl, sg, i, j) {
 503                 size_t bytes;
 504
 505                 bytes = iopgtable_clear_entry(obj, da);
 506
 507                 BUG_ON(!iopgsz_ok(bytes));
 508
 509                 da += bytes;
 510         }
 511         return err;
 512 }
 513
 514 /* release 'da' <-> 'pa' mapping */
 515 static void unmap_iovm_area(struct iommu *obj, struct iovm_struct *area)
 516 {
 517         u32 start;
 518         size_t total = area->da_end - area->da_start;
 519
 520         BUG_ON((!total) || !IS_ALIGNED(total, PAGE_SIZE));
 521
 522         start = area->da_start;
 523         while (total > 0) {
 524                 size_t bytes;
 525
 526                 bytes = iopgtable_clear_entry(obj, start);
 527                 if (bytes == 0)
 528                         bytes = PAGE_SIZE;
 529                 else
 530                         dev_dbg(obj->dev, "%s: unmap %08x(%x) %08x\n",
 531                                 __func__, start, bytes, area->flags);
 532
 533                 BUG_ON(!IS_ALIGNED(bytes, PAGE_SIZE));
 534
 535                 total -= bytes;
 536                 start += bytes;
 537         }
 538         BUG_ON(total);
 539 }
 540
 541 /* template function for all unmapping */
 542 static struct sg_table *unmap_vm_area(struct iommu *obj, const u32 da,
 543                                       void (*fn)(const void *), u32 flags)
 544 {
 545         struct sg_table *sgt = NULL;
 546         struct iovm_struct *area;
 547
 548         if (!IS_ALIGNED(da, PAGE_SIZE)) {
 549                 dev_err(obj->dev, "%s: alignment err(%08x)\n", __func__, da);
 550                 return NULL;
 551         }
 552
 553         mutex_lock(&obj->mmap_lock);
 554
 555         area = __find_iovm_area(obj, da);
 556         if (!area) {
 557                 dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
 558                 goto out;
 559         }
 560
 561         if ((area->flags & flags) != flags) {
 562                 dev_err(obj->dev, "%s: wrong flags(%08x)\n", __func__,
 563                         area->flags);
 564                 goto out;
 565         }
 566         sgt = (struct sg_table *)area->sgt;
 567
 568         unmap_iovm_area(obj, area);
 569
 570         fn(area->va);
 571
 572         dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n", __func__,
 573                 area->da_start, da, area->da_end,
 574                 area->da_end - area->da_start, area->flags);
 575
 576         free_iovm_area(obj, area);
 577 out:
 578         mutex_unlock(&obj->mmap_lock);
 579
 580         return sgt;
 581 }
 582
 583 static u32 map_iommu_region(struct iommu *obj, u32 da,
 584               const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
 585 {
 586         int err = -ENOMEM;
 587         struct iovm_struct *new;
 588
 589         mutex_lock(&obj->mmap_lock);
 590
 591         new = alloc_iovm_area(obj, da, bytes, flags);
 592         if (IS_ERR(new)) {
 593                 err = PTR_ERR(new);
 594                 goto err_alloc_iovma;
 595         }
 596         new->va = va;
 597         new->sgt = sgt;
 598
 599         if (map_iovm_area(obj, new, sgt, new->flags))
 600                 goto err_map;
 601
 602         mutex_unlock(&obj->mmap_lock);
 603
 604         dev_dbg(obj->dev, "%s: da:%08x(%x) flags:%08x va:%p\n",
 605                 __func__, new->da_start, bytes, new->flags, va);
 606
 607         return new->da_start;
 608
 609 err_map:
 610         free_iovm_area(obj, new);
 611 err_alloc_iovma:
 612         mutex_unlock(&obj->mmap_lock);
 613         return err;
 614 }
 615
 616 static inline u32 __iommu_vmap(struct iommu *obj, u32 da,
 617                  const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
 618 {
 619         return map_iommu_region(obj, da, sgt, va, bytes, flags);
 620 }
 621
 622 /**
 623  * iommu_vmap  -  (d)-(p)-(v) address mapper
 624  * @obj:        objective iommu
 625  * @sgt:        address of scatter gather table
 626  * @flags:      iovma and page property
 627  *
 628  * Creates 1-n-1 mapping with given @sgt and returns @da.
 629  * All @sgt element must be io page size aligned.
 630  */
 631 u32 iommu_vmap(struct iommu *obj, u32 da, const struct sg_table *sgt,
 632                  u32 flags)
 633 {
 634         size_t bytes;
 635         void *va = NULL;
 636
 637         if (!obj || !obj->dev || !sgt)
 638                 return -EINVAL;
 639
 640         bytes = sgtable_len(sgt);
 641         if (!bytes)
 642                 return -EINVAL;
 643         bytes = PAGE_ALIGN(bytes);
 644
 645         if (flags & IOVMF_MMIO) {
 646                 va = vmap_sg(sgt);
 647                 if (IS_ERR(va))
 648                         return PTR_ERR(va);
 649         }
 650
 651         flags |= IOVMF_DISCONT;
 652         flags |= IOVMF_MMIO;
 653
 654         da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
 655         if (IS_ERR_VALUE(da))
 656                 vunmap_sg(va);
 657
 658         return da;
 659 }
 660 EXPORT_SYMBOL_GPL(iommu_vmap);
 661
 662 /**
 663  * iommu_vunmap  -  release virtual mapping obtained by 'iommu_vmap()'
 664  * @obj:        objective iommu
 665  * @da:         iommu device virtual address
 666  *
 667  * Free the iommu virtually contiguous memory area starting at
 668  * @da, which was returned by 'iommu_vmap()'.
 669  */
 670 struct sg_table *iommu_vunmap(struct iommu *obj, u32 da)
 671 {
 672         struct sg_table *sgt;
 673         /*
 674          * 'sgt' is allocated before 'iommu_vmalloc()' is called.
 675          * Just returns 'sgt' to the caller to free
 676          */
 677         sgt = unmap_vm_area(obj, da, vunmap_sg, IOVMF_DISCONT | IOVMF_MMIO);
 678         if (!sgt)
 679                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 680         return sgt;
 681 }
 682 EXPORT_SYMBOL_GPL(iommu_vunmap);
 683
 684 /**
 685  * iommu_vmalloc  -  (d)-(p)-(v) address allocator and mapper
 686  * @obj:        objective iommu
 687  * @da:         contiguous iommu virtual memory
 688  * @bytes:      allocation size
 689  * @flags:      iovma and page property
 690  *
 691  * Allocate @bytes linearly and creates 1-n-1 mapping and returns
 692  * @da again, which might be adjusted if 'IOVMF_DA_FIXED' is not set.
 693  */
 694 u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 695 {
 696         void *va;
 697         struct sg_table *sgt;
 698
 699         if (!obj || !obj->dev || !bytes)
 700                 return -EINVAL;
 701
 702         bytes = PAGE_ALIGN(bytes);
 703
 704         va = vmalloc(bytes);
 705         if (!va)
 706                 return -ENOMEM;
 707
 708         flags |= IOVMF_DISCONT;
 709         flags |= IOVMF_ALLOC;
 710
 711         sgt = sgtable_alloc(bytes, flags, da, 0);
 712         if (IS_ERR(sgt)) {
 713                 da = PTR_ERR(sgt);
 714                 goto err_sgt_alloc;
 715         }
 716         sgtable_fill_vmalloc(sgt, va);
 717
 718         da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
 719         if (IS_ERR_VALUE(da))
 720                 goto err_iommu_vmap;
 721
 722         return da;
 723
 724 err_iommu_vmap:
 725         sgtable_drain_vmalloc(sgt);
 726         sgtable_free(sgt);
 727 err_sgt_alloc:
 728         vfree(va);
 729         return da;
 730 }
 731 EXPORT_SYMBOL_GPL(iommu_vmalloc);
 732
 733 /**
 734  * iommu_vfree  -  release memory allocated by 'iommu_vmalloc()'
 735  * @obj:        objective iommu
 736  * @da:         iommu device virtual address
 737  *
 738  * Frees the iommu virtually continuous memory area starting at
 739  * @da, as obtained from 'iommu_vmalloc()'.
 740  */
 741 void iommu_vfree(struct iommu *obj, const u32 da)
 742 {
 743         struct sg_table *sgt;
 744
 745         sgt = unmap_vm_area(obj, da, vfree, IOVMF_DISCONT | IOVMF_ALLOC);
 746         if (!sgt)
 747                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 748         sgtable_free(sgt);
 749 }
 750 EXPORT_SYMBOL_GPL(iommu_vfree);
 751
 752 static u32 __iommu_kmap(struct iommu *obj, u32 da, u32 pa, void *va,
 753                           size_t bytes, u32 flags)
 754 {
 755         struct sg_table *sgt;
 756
 757         sgt = sgtable_alloc(bytes, flags, da, pa);
 758         if (IS_ERR(sgt))
 759                 return PTR_ERR(sgt);
 760
 761         sgtable_fill_kmalloc(sgt, pa, da, bytes);
 762
 763         da = map_iommu_region(obj, da, sgt, va, bytes, flags);
 764         if (IS_ERR_VALUE(da)) {
 765                 sgtable_drain_kmalloc(sgt);
 766                 sgtable_free(sgt);
 767         }
 768
 769         return da;
 770 }
 771
 772 /**
 773  * iommu_kmap  -  (d)-(p)-(v) address mapper
 774  * @obj:        objective iommu
 775  * @da:         contiguous iommu virtual memory
 776  * @pa:         contiguous physical memory
 777  * @flags:      iovma and page property
 778  *
 779  * Creates 1-1-1 mapping and returns @da again, which can be
 780  * adjusted if 'IOVMF_DA_FIXED' is not set.
 781  */
 782 u32 iommu_kmap(struct iommu *obj, u32 da, u32 pa, size_t bytes,
 783                  u32 flags)
 784 {
 785         void *va;
 786
 787         if (!obj || !obj->dev || !bytes)
 788                 return -EINVAL;
 789
 790         bytes = PAGE_ALIGN(bytes);
 791
 792         va = ioremap(pa, bytes);
 793         if (!va)
 794                 return -ENOMEM;
 795
 796         flags |= IOVMF_LINEAR;
 797         flags |= IOVMF_MMIO;
 798
 799         da = __iommu_kmap(obj, da, pa, va, bytes, flags);
 800         if (IS_ERR_VALUE(da))
 801                 iounmap(va);
 802
 803         return da;
 804 }
 805 EXPORT_SYMBOL_GPL(iommu_kmap);
 806
 807 /**
 808  * iommu_kunmap  -  release virtual mapping obtained by 'iommu_kmap()'
 809  * @obj:        objective iommu
 810  * @da:         iommu device virtual address
 811  *
 812  * Frees the iommu virtually contiguous memory area starting at
 813  * @da, which was passed to and was returned by'iommu_kmap()'.
 814  */
 815 void iommu_kunmap(struct iommu *obj, u32 da)
 816 {
 817         struct sg_table *sgt;
 818         typedef void (*func_t)(const void *);
 819
 820         sgt = unmap_vm_area(obj, da, (func_t)iounmap,
 821                             IOVMF_LINEAR | IOVMF_MMIO);
 822         if (!sgt)
 823                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 824         sgtable_free(sgt);
 825 }
 826 EXPORT_SYMBOL_GPL(iommu_kunmap);
 827
 828 /**
 829  * iommu_kmalloc  -  (d)-(p)-(v) address allocator and mapper
 830  * @obj:        objective iommu
 831  * @da:         contiguous iommu virtual memory
 832  * @bytes:      bytes for allocation
 833  * @flags:      iovma and page property
 834  *
 835  * Allocate @bytes linearly and creates 1-1-1 mapping and returns
 836  * @da again, which might be adjusted if 'IOVMF_DA_FIXED' is not set.
 837  */
 838 u32 iommu_kmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 839 {
 840         void *va;
 841         u32 pa;
 842
 843         if (!obj || !obj->dev || !bytes)
 844                 return -EINVAL;
 845
 846         bytes = PAGE_ALIGN(bytes);
 847
 848         va = kmalloc(bytes, GFP_KERNEL | GFP_DMA);
 849         if (!va)
 850                 return -ENOMEM;
 851         pa = virt_to_phys(va);
 852
 853         flags |= IOVMF_LINEAR;
 854         flags |= IOVMF_ALLOC;
 855
 856         da = __iommu_kmap(obj, da, pa, va, bytes, flags);
 857         if (IS_ERR_VALUE(da))
 858                 kfree(va);
 859
 860         return da;
 861 }
 862 EXPORT_SYMBOL_GPL(iommu_kmalloc);
 863
 864 /**
 865  * iommu_kfree  -  release virtual mapping obtained by 'iommu_kmalloc()'
 866  * @obj:        objective iommu
 867  * @da:         iommu device virtual address
 868  *
 869  * Frees the iommu virtually contiguous memory area starting at
 870  * @da, which was passed to and was returned by'iommu_kmalloc()'.
 871  */
 872 void iommu_kfree(struct iommu *obj, u32 da)
 873 {
 874         struct sg_table *sgt;
 875
 876         sgt = unmap_vm_area(obj, da, kfree, IOVMF_LINEAR | IOVMF_ALLOC);
 877         if (!sgt)
 878                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 879         sgtable_free(sgt);
 880 }
 881 EXPORT_SYMBOL_GPL(iommu_kfree);
 882
 883
 884 static int __init iovmm_init(void)
 885 {
 886         const unsigned long flags = SLAB_HWCACHE_ALIGN;
 887         struct kmem_cache *p;
 888
 889         p = kmem_cache_create("iovm_area_cache", sizeof(struct iovm_struct), 0,
 890                               flags, NULL);
 891         if (!p)
 892                 return -ENOMEM;
 893         iovm_area_cachep = p;
 894
 895         return 0;
 896 }
 897 module_init(iovmm_init);
 898
 899 static void __exit iovmm_exit(void)
 900 {
 901         kmem_cache_destroy(iovm_area_cachep);
 902 }
 903 module_exit(iovmm_exit);
 904
 905 MODULE_DESCRIPTION("omap iommu: simple virtual address space management");
 906 MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
 907 MODULE_LICENSE("GPL v2");