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/vmalloc.h>
  15 #include <linux/device.h>
  16 #include <linux/scatterlist.h>
  17
  18 #include <asm/cacheflush.h>
  19 #include <asm/mach/map.h>
  20
  21 #include <mach/iommu.h>
  22 #include <mach/iovmm.h>
  23
  24 #include "iopgtable.h"
  25
  26 /*
  27  * A device driver needs to create address mappings between:
  28  *
  29  * - iommu/device address
  30  * - physical address
  31  * - mpu virtual address
  32  *
  33  * There are 4 possible patterns for them:
  34  *
  35  *    |iova/                      mapping               iommu_          page
  36  *    | da      pa      va      (d)-(p)-(v)             function        type
  37  *  ---------------------------------------------------------------------------
  38  *  1 | c       c       c        1 - 1 - 1        _kmap() / _kunmap()   s
  39  *  2 | c       c,a     c        1 - 1 - 1      _kmalloc()/ _kfree()    s
  40  *  3 | c       d       c        1 - n - 1        _vmap() / _vunmap()   s
  41  *  4 | c       d,a     c        1 - n - 1      _vmalloc()/ _vfree()    n*
  42  *
  43  *
  44  *      'iova': device iommu virtual address
  45  *      'da':   alias of 'iova'
  46  *      'pa':   physical address
  47  *      'va':   mpu virtual address
  48  *
  49  *      'c':    contiguous memory area
  50  *      'd':    dicontiguous memory area
  51  *      'a':    anonymous memory allocation
  52  *      '()':   optional feature
  53  *
  54  *      'n':    a normal page(4KB) size is used.
  55  *      's':    multiple iommu superpage(16MB, 1MB, 64KB, 4KB) size is used.
  56  *
  57  *      '*':    not yet, but feasible.
  58  */
  59
  60 static struct kmem_cache *iovm_area_cachep;
  61
  62 /* return total bytes of sg buffers */
  63 static size_t sgtable_len(const struct sg_table *sgt)
  64 {
  65         unsigned int i, total = 0;
  66         struct scatterlist *sg;
  67
  68         if (!sgt)
  69                 return 0;
  70
  71         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
  72                 size_t bytes;
  73
  74                 bytes = sg_dma_len(sg);
  75
  76                 if (!iopgsz_ok(bytes)) {
  77                         pr_err("%s: sg[%d] not iommu pagesize(%x)\n",
  78                                __func__, i, bytes);
  79                         return 0;
  80                 }
  81
  82                 total += bytes;
  83         }
  84
  85         return total;
  86 }
  87 #define sgtable_ok(x)   (!!sgtable_len(x))
  88
  89 /*
  90  * calculate the optimal number sg elements from total bytes based on
  91  * iommu superpages
  92  */
  93 static unsigned int sgtable_nents(size_t bytes)
  94 {
  95         int i;
  96         unsigned int nr_entries;
  97         const unsigned long pagesize[] = { SZ_16M, SZ_1M, SZ_64K, SZ_4K, };
  98
  99         if (!IS_ALIGNED(bytes, PAGE_SIZE)) {
 100                 pr_err("%s: wrong size %08x\n", __func__, bytes);
 101                 return 0;
 102         }
 103
 104         nr_entries = 0;
 105         for (i = 0; i < ARRAY_SIZE(pagesize); i++) {
 106                 if (bytes >= pagesize[i]) {
 107                         nr_entries += (bytes / pagesize[i]);
 108                         bytes %= pagesize[i];
 109                 }
 110         }
 111         BUG_ON(bytes);
 112
 113         return nr_entries;
 114 }
 115
 116 /* allocate and initialize sg_table header(a kind of 'superblock') */
 117 static struct sg_table *sgtable_alloc(const size_t bytes, u32 flags)
 118 {
 119         unsigned int nr_entries;
 120         int err;
 121         struct sg_table *sgt;
 122
 123         if (!bytes)
 124                 return ERR_PTR(-EINVAL);
 125
 126         if (!IS_ALIGNED(bytes, PAGE_SIZE))
 127                 return ERR_PTR(-EINVAL);
 128
 129         /* FIXME: IOVMF_DA_FIXED should support 'superpages' */
 130         if ((flags & IOVMF_LINEAR) && (flags & IOVMF_DA_ANON)) {
 131                 nr_entries = sgtable_nents(bytes);
 132                 if (!nr_entries)
 133                         return ERR_PTR(-EINVAL);
 134         } else
 135                 nr_entries =  bytes / PAGE_SIZE;
 136
 137         sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
 138         if (!sgt)
 139                 return ERR_PTR(-ENOMEM);
 140
 141         err = sg_alloc_table(sgt, nr_entries, GFP_KERNEL);
 142         if (err)
 143                 return ERR_PTR(err);
 144
 145         pr_debug("%s: sgt:%p(%d entries)\n", __func__, sgt, nr_entries);
 146
 147         return sgt;
 148 }
 149
 150 /* free sg_table header(a kind of superblock) */
 151 static void sgtable_free(struct sg_table *sgt)
 152 {
 153         if (!sgt)
 154                 return;
 155
 156         sg_free_table(sgt);
 157         kfree(sgt);
 158
 159         pr_debug("%s: sgt:%p\n", __func__, sgt);
 160 }
 161
 162 /* map 'sglist' to a contiguous mpu virtual area and return 'va' */
 163 static void *vmap_sg(const struct sg_table *sgt)
 164 {
 165         u32 va;
 166         size_t total;
 167         unsigned int i;
 168         struct scatterlist *sg;
 169         struct vm_struct *new;
 170         const struct mem_type *mtype;
 171
 172         mtype = get_mem_type(MT_DEVICE);
 173         if (!mtype)
 174                 return ERR_PTR(-EINVAL);
 175
 176         total = sgtable_len(sgt);
 177         if (!total)
 178                 return ERR_PTR(-EINVAL);
 179
 180         new = __get_vm_area(total, VM_IOREMAP, VMALLOC_START, VMALLOC_END);
 181         if (!new)
 182                 return ERR_PTR(-ENOMEM);
 183         va = (u32)new->addr;
 184
 185         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 186                 size_t bytes;
 187                 u32 pa;
 188                 int err;
 189
 190                 pa = sg_phys(sg);
 191                 bytes = sg_dma_len(sg);
 192
 193                 BUG_ON(bytes != PAGE_SIZE);
 194
 195                 err = ioremap_page(va,  pa, mtype);
 196                 if (err)
 197                         goto err_out;
 198
 199                 va += bytes;
 200         }
 201
 202         flush_cache_vmap(new->addr, new->addr + total);
 203         return new->addr;
 204
 205 err_out:
 206         WARN_ON(1); /* FIXME: cleanup some mpu mappings */
 207         vunmap(new->addr);
 208         return ERR_PTR(-EAGAIN);
 209 }
 210
 211 static inline void vunmap_sg(const void *va)
 212 {
 213         vunmap(va);
 214 }
 215
 216 static struct iovm_struct *__find_iovm_area(struct iommu *obj, const u32 da)
 217 {
 218         struct iovm_struct *tmp;
 219
 220         list_for_each_entry(tmp, &obj->mmap, list) {
 221                 if ((da >= tmp->da_start) && (da < tmp->da_end)) {
 222                         size_t len;
 223
 224                         len = tmp->da_end - tmp->da_start;
 225
 226                         dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n",
 227                                 __func__, tmp->da_start, da, tmp->da_end, len,
 228                                 tmp->flags);
 229
 230                         return tmp;
 231                 }
 232         }
 233
 234         return NULL;
 235 }
 236
 237 /**
 238  * find_iovm_area  -  find iovma which includes @da
 239  * @da:         iommu device virtual address
 240  *
 241  * Find the existing iovma starting at @da
 242  */
 243 struct iovm_struct *find_iovm_area(struct iommu *obj, u32 da)
 244 {
 245         struct iovm_struct *area;
 246
 247         mutex_lock(&obj->mmap_lock);
 248         area = __find_iovm_area(obj, da);
 249         mutex_unlock(&obj->mmap_lock);
 250
 251         return area;
 252 }
 253 EXPORT_SYMBOL_GPL(find_iovm_area);
 254
 255 /*
 256  * This finds the hole(area) which fits the requested address and len
 257  * in iovmas mmap, and returns the new allocated iovma.
 258  */
 259 static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
 260                                            size_t bytes, u32 flags)
 261 {
 262         struct iovm_struct *new, *tmp;
 263         u32 start, prev_end, alignement;
 264
 265         if (!obj || !bytes)
 266                 return ERR_PTR(-EINVAL);
 267
 268         start = da;
 269         alignement = PAGE_SIZE;
 270
 271         if (flags & IOVMF_DA_ANON) {
 272                 /*
 273                  * Reserve the first page for NULL
 274                  */
 275                 start = PAGE_SIZE;
 276                 if (flags & IOVMF_LINEAR)
 277                         alignement = iopgsz_max(bytes);
 278                 start = roundup(start, alignement);
 279         }
 280
 281         tmp = NULL;
 282         if (list_empty(&obj->mmap))
 283                 goto found;
 284
 285         prev_end = 0;
 286         list_for_each_entry(tmp, &obj->mmap, list) {
 287
 288                 if ((prev_end <= start) && (start + bytes < tmp->da_start))
 289                         goto found;
 290
 291                 if (flags & IOVMF_DA_ANON)
 292                         start = roundup(tmp->da_end, alignement);
 293
 294                 prev_end = tmp->da_end;
 295         }
 296
 297         if ((start >= prev_end) && (ULONG_MAX - start >= bytes))
 298                 goto found;
 299
 300         dev_dbg(obj->dev, "%s: no space to fit %08x(%x) flags: %08x\n",
 301                 __func__, da, bytes, flags);
 302
 303         return ERR_PTR(-EINVAL);
 304
 305 found:
 306         new = kmem_cache_zalloc(iovm_area_cachep, GFP_KERNEL);
 307         if (!new)
 308                 return ERR_PTR(-ENOMEM);
 309
 310         new->iommu = obj;
 311         new->da_start = start;
 312         new->da_end = start + bytes;
 313         new->flags = flags;
 314
 315         /*
 316          * keep ascending order of iovmas
 317          */
 318         if (tmp)
 319                 list_add_tail(&new->list, &tmp->list);
 320         else
 321                 list_add(&new->list, &obj->mmap);
 322
 323         dev_dbg(obj->dev, "%s: found %08x-%08x-%08x(%x) %08x\n",
 324                 __func__, new->da_start, start, new->da_end, bytes, flags);
 325
 326         return new;
 327 }
 328
 329 static void free_iovm_area(struct iommu *obj, struct iovm_struct *area)
 330 {
 331         size_t bytes;
 332
 333         BUG_ON(!obj || !area);
 334
 335         bytes = area->da_end - area->da_start;
 336
 337         dev_dbg(obj->dev, "%s: %08x-%08x(%x) %08x\n",
 338                 __func__, area->da_start, area->da_end, bytes, area->flags);
 339
 340         list_del(&area->list);
 341         kmem_cache_free(iovm_area_cachep, area);
 342 }
 343
 344 /**
 345  * da_to_va - convert (d) to (v)
 346  * @obj:        objective iommu
 347  * @da:         iommu device virtual address
 348  * @va:         mpu virtual address
 349  *
 350  * Returns mpu virtual addr which corresponds to a given device virtual addr
 351  */
 352 void *da_to_va(struct iommu *obj, u32 da)
 353 {
 354         void *va = NULL;
 355         struct iovm_struct *area;
 356
 357         mutex_lock(&obj->mmap_lock);
 358
 359         area = __find_iovm_area(obj, da);
 360         if (!area) {
 361                 dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
 362                 goto out;
 363         }
 364         va = area->va;
 365         mutex_unlock(&obj->mmap_lock);
 366 out:
 367         return va;
 368 }
 369 EXPORT_SYMBOL_GPL(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 '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         flush_cache_vmap(_va, va_end);
 394 }
 395
 396 static inline void sgtable_drain_vmalloc(struct sg_table *sgt)
 397 {
 398         /*
 399          * Actually this is not necessary at all, just exists for
 400          * consistency of the code readibility.
 401          */
 402         BUG_ON(!sgt);
 403 }
 404
 405 static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, size_t len)
 406 {
 407         unsigned int i;
 408         struct scatterlist *sg;
 409         void *va;
 410
 411         va = phys_to_virt(pa);
 412
 413         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 414                 size_t bytes;
 415
 416                 bytes = iopgsz_max(len);
 417
 418                 BUG_ON(!iopgsz_ok(bytes));
 419
 420                 sg_set_buf(sg, phys_to_virt(pa), bytes);
 421                 /*
 422                  * 'pa' is cotinuous(linear).
 423                  */
 424                 pa += bytes;
 425                 len -= bytes;
 426         }
 427         BUG_ON(len);
 428
 429         clean_dcache_area(va, len);
 430 }
 431
 432 static inline void sgtable_drain_kmalloc(struct sg_table *sgt)
 433 {
 434         /*
 435          * Actually this is not necessary at all, just exists for
 436          * consistency of the code readibility
 437          */
 438         BUG_ON(!sgt);
 439 }
 440
 441 /* create 'da' <-> 'pa' mapping from 'sgt' */
 442 static int map_iovm_area(struct iommu *obj, struct iovm_struct *new,
 443                          const struct sg_table *sgt, u32 flags)
 444 {
 445         int err;
 446         unsigned int i, j;
 447         struct scatterlist *sg;
 448         u32 da = new->da_start;
 449
 450         if (!obj || !new || !sgt)
 451                 return -EINVAL;
 452
 453         BUG_ON(!sgtable_ok(sgt));
 454
 455         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 456                 u32 pa;
 457                 int pgsz;
 458                 size_t bytes;
 459                 struct iotlb_entry e;
 460
 461                 pa = sg_phys(sg);
 462                 bytes = sg_dma_len(sg);
 463
 464                 flags &= ~IOVMF_PGSZ_MASK;
 465                 pgsz = bytes_to_iopgsz(bytes);
 466                 if (pgsz < 0)
 467                         goto err_out;
 468                 flags |= pgsz;
 469
 470                 pr_debug("%s: [%d] %08x %08x(%x)\n", __func__,
 471                          i, da, pa, bytes);
 472
 473                 iotlb_init_entry(&e, da, pa, flags);
 474                 err = iopgtable_store_entry(obj, &e);
 475                 if (err)
 476                         goto err_out;
 477
 478                 da += bytes;
 479         }
 480         return 0;
 481
 482 err_out:
 483         da = new->da_start;
 484
 485         for_each_sg(sgt->sgl, sg, i, j) {
 486                 size_t bytes;
 487
 488                 bytes = iopgtable_clear_entry(obj, da);
 489
 490                 BUG_ON(!iopgsz_ok(bytes));
 491
 492                 da += bytes;
 493         }
 494         return err;
 495 }
 496
 497 /* release 'da' <-> 'pa' mapping */
 498 static void unmap_iovm_area(struct iommu *obj, struct iovm_struct *area)
 499 {
 500         u32 start;
 501         size_t total = area->da_end - area->da_start;
 502
 503         BUG_ON((!total) || !IS_ALIGNED(total, PAGE_SIZE));
 504
 505         start = area->da_start;
 506         while (total > 0) {
 507                 size_t bytes;
 508
 509                 bytes = iopgtable_clear_entry(obj, start);
 510                 if (bytes == 0)
 511                         bytes = PAGE_SIZE;
 512                 else
 513                         dev_dbg(obj->dev, "%s: unmap %08x(%x) %08x\n",
 514                                 __func__, start, bytes, area->flags);
 515
 516                 BUG_ON(!IS_ALIGNED(bytes, PAGE_SIZE));
 517
 518                 total -= bytes;
 519                 start += bytes;
 520         }
 521         BUG_ON(total);
 522 }
 523
 524 /* template function for all unmapping */
 525 static struct sg_table *unmap_vm_area(struct iommu *obj, const u32 da,
 526                                       void (*fn)(const void *), u32 flags)
 527 {
 528         struct sg_table *sgt = NULL;
 529         struct iovm_struct *area;
 530
 531         if (!IS_ALIGNED(da, PAGE_SIZE)) {
 532                 dev_err(obj->dev, "%s: alignment err(%08x)\n", __func__, da);
 533                 return NULL;
 534         }
 535
 536         mutex_lock(&obj->mmap_lock);
 537
 538         area = __find_iovm_area(obj, da);
 539         if (!area) {
 540                 dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
 541                 goto out;
 542         }
 543
 544         if ((area->flags & flags) != flags) {
 545                 dev_err(obj->dev, "%s: wrong flags(%08x)\n", __func__,
 546                         area->flags);
 547                 goto out;
 548         }
 549         sgt = (struct sg_table *)area->sgt;
 550
 551         unmap_iovm_area(obj, area);
 552
 553         fn(area->va);
 554
 555         dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n", __func__,
 556                 area->da_start, da, area->da_end,
 557                 area->da_end - area->da_start, area->flags);
 558
 559         free_iovm_area(obj, area);
 560 out:
 561         mutex_unlock(&obj->mmap_lock);
 562
 563         return sgt;
 564 }
 565
 566 static u32 map_iommu_region(struct iommu *obj, u32 da,
 567               const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
 568 {
 569         int err = -ENOMEM;
 570         struct iovm_struct *new;
 571
 572         mutex_lock(&obj->mmap_lock);
 573
 574         new = alloc_iovm_area(obj, da, bytes, flags);
 575         if (IS_ERR(new)) {
 576                 err = PTR_ERR(new);
 577                 goto err_alloc_iovma;
 578         }
 579         new->va = va;
 580         new->sgt = sgt;
 581
 582         if (map_iovm_area(obj, new, sgt, new->flags))
 583                 goto err_map;
 584
 585         mutex_unlock(&obj->mmap_lock);
 586
 587         dev_dbg(obj->dev, "%s: da:%08x(%x) flags:%08x va:%p\n",
 588                 __func__, new->da_start, bytes, new->flags, va);
 589
 590         return new->da_start;
 591
 592 err_map:
 593         free_iovm_area(obj, new);
 594 err_alloc_iovma:
 595         mutex_unlock(&obj->mmap_lock);
 596         return err;
 597 }
 598
 599 static inline u32 __iommu_vmap(struct iommu *obj, u32 da,
 600                  const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
 601 {
 602         return map_iommu_region(obj, da, sgt, va, bytes, flags);
 603 }
 604
 605 /**
 606  * iommu_vmap  -  (d)-(p)-(v) address mapper
 607  * @obj:        objective iommu
 608  * @sgt:        address of scatter gather table
 609  * @flags:      iovma and page property
 610  *
 611  * Creates 1-n-1 mapping with given @sgt and returns @da.
 612  * All @sgt element must be io page size aligned.
 613  */
 614 u32 iommu_vmap(struct iommu *obj, u32 da, const struct sg_table *sgt,
 615                  u32 flags)
 616 {
 617         size_t bytes;
 618         void *va;
 619
 620         if (!obj || !obj->dev || !sgt)
 621                 return -EINVAL;
 622
 623         bytes = sgtable_len(sgt);
 624         if (!bytes)
 625                 return -EINVAL;
 626         bytes = PAGE_ALIGN(bytes);
 627
 628         va = vmap_sg(sgt);
 629         if (IS_ERR(va))
 630                 return PTR_ERR(va);
 631
 632         flags &= IOVMF_HW_MASK;
 633         flags |= IOVMF_DISCONT;
 634         flags |= IOVMF_MMIO;
 635         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 636
 637         da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
 638         if (IS_ERR_VALUE(da))
 639                 vunmap_sg(va);
 640
 641         return da;
 642 }
 643 EXPORT_SYMBOL_GPL(iommu_vmap);
 644
 645 /**
 646  * iommu_vunmap  -  release virtual mapping obtained by 'iommu_vmap()'
 647  * @obj:        objective iommu
 648  * @da:         iommu device virtual address
 649  *
 650  * Free the iommu virtually contiguous memory area starting at
 651  * @da, which was returned by 'iommu_vmap()'.
 652  */
 653 struct sg_table *iommu_vunmap(struct iommu *obj, u32 da)
 654 {
 655         struct sg_table *sgt;
 656         /*
 657          * 'sgt' is allocated before 'iommu_vmalloc()' is called.
 658          * Just returns 'sgt' to the caller to free
 659          */
 660         sgt = unmap_vm_area(obj, da, vunmap_sg, IOVMF_DISCONT | IOVMF_MMIO);
 661         if (!sgt)
 662                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 663         return sgt;
 664 }
 665 EXPORT_SYMBOL_GPL(iommu_vunmap);
 666
 667 /**
 668  * iommu_vmalloc  -  (d)-(p)-(v) address allocator and mapper
 669  * @obj:        objective iommu
 670  * @da:         contiguous iommu virtual memory
 671  * @bytes:      allocation size
 672  * @flags:      iovma and page property
 673  *
 674  * Allocate @bytes linearly and creates 1-n-1 mapping and returns
 675  * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
 676  */
 677 u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 678 {
 679         void *va;
 680         struct sg_table *sgt;
 681
 682         if (!obj || !obj->dev || !bytes)
 683                 return -EINVAL;
 684
 685         bytes = PAGE_ALIGN(bytes);
 686
 687         va = vmalloc(bytes);
 688         if (!va)
 689                 return -ENOMEM;
 690
 691         sgt = sgtable_alloc(bytes, flags);
 692         if (IS_ERR(sgt)) {
 693                 da = PTR_ERR(sgt);
 694                 goto err_sgt_alloc;
 695         }
 696         sgtable_fill_vmalloc(sgt, va);
 697
 698         flags &= IOVMF_HW_MASK;
 699         flags |= IOVMF_DISCONT;
 700         flags |= IOVMF_ALLOC;
 701         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 702
 703         da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
 704         if (IS_ERR_VALUE(da))
 705                 goto err_iommu_vmap;
 706
 707         return da;
 708
 709 err_iommu_vmap:
 710         sgtable_drain_vmalloc(sgt);
 711         sgtable_free(sgt);
 712 err_sgt_alloc:
 713         vfree(va);
 714         return da;
 715 }
 716 EXPORT_SYMBOL_GPL(iommu_vmalloc);
 717
 718 /**
 719  * iommu_vfree  -  release memory allocated by 'iommu_vmalloc()'
 720  * @obj:        objective iommu
 721  * @da:         iommu device virtual address
 722  *
 723  * Frees the iommu virtually continuous memory area starting at
 724  * @da, as obtained from 'iommu_vmalloc()'.
 725  */
 726 void iommu_vfree(struct iommu *obj, const u32 da)
 727 {
 728         struct sg_table *sgt;
 729
 730         sgt = unmap_vm_area(obj, da, vfree, IOVMF_DISCONT | IOVMF_ALLOC);
 731         if (!sgt)
 732                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 733         sgtable_free(sgt);
 734 }
 735 EXPORT_SYMBOL_GPL(iommu_vfree);
 736
 737 static u32 __iommu_kmap(struct iommu *obj, u32 da, u32 pa, void *va,
 738                           size_t bytes, u32 flags)
 739 {
 740         struct sg_table *sgt;
 741
 742         sgt = sgtable_alloc(bytes, flags);
 743         if (IS_ERR(sgt))
 744                 return PTR_ERR(sgt);
 745
 746         sgtable_fill_kmalloc(sgt, pa, bytes);
 747
 748         da = map_iommu_region(obj, da, sgt, va, bytes, flags);
 749         if (IS_ERR_VALUE(da)) {
 750                 sgtable_drain_kmalloc(sgt);
 751                 sgtable_free(sgt);
 752         }
 753
 754         return da;
 755 }
 756
 757 /**
 758  * iommu_kmap  -  (d)-(p)-(v) address mapper
 759  * @obj:        objective iommu
 760  * @da:         contiguous iommu virtual memory
 761  * @pa:         contiguous physical memory
 762  * @flags:      iovma and page property
 763  *
 764  * Creates 1-1-1 mapping and returns @da again, which can be
 765  * adjusted if 'IOVMF_DA_ANON' is set.
 766  */
 767 u32 iommu_kmap(struct iommu *obj, u32 da, u32 pa, size_t bytes,
 768                  u32 flags)
 769 {
 770         void *va;
 771
 772         if (!obj || !obj->dev || !bytes)
 773                 return -EINVAL;
 774
 775         bytes = PAGE_ALIGN(bytes);
 776
 777         va = ioremap(pa, bytes);
 778         if (!va)
 779                 return -ENOMEM;
 780
 781         flags &= IOVMF_HW_MASK;
 782         flags |= IOVMF_LINEAR;
 783         flags |= IOVMF_MMIO;
 784         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 785
 786         da = __iommu_kmap(obj, da, pa, va, bytes, flags);
 787         if (IS_ERR_VALUE(da))
 788                 iounmap(va);
 789
 790         return da;
 791 }
 792 EXPORT_SYMBOL_GPL(iommu_kmap);
 793
 794 /**
 795  * iommu_kunmap  -  release virtual mapping obtained by 'iommu_kmap()'
 796  * @obj:        objective iommu
 797  * @da:         iommu device virtual address
 798  *
 799  * Frees the iommu virtually contiguous memory area starting at
 800  * @da, which was passed to and was returned by'iommu_kmap()'.
 801  */
 802 void iommu_kunmap(struct iommu *obj, u32 da)
 803 {
 804         struct sg_table *sgt;
 805         typedef void (*func_t)(const void *);
 806
 807         sgt = unmap_vm_area(obj, da, (func_t)__iounmap,
 808                             IOVMF_LINEAR | IOVMF_MMIO);
 809         if (!sgt)
 810                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 811         sgtable_free(sgt);
 812 }
 813 EXPORT_SYMBOL_GPL(iommu_kunmap);
 814
 815 /**
 816  * iommu_kmalloc  -  (d)-(p)-(v) address allocator and mapper
 817  * @obj:        objective iommu
 818  * @da:         contiguous iommu virtual memory
 819  * @bytes:      bytes for allocation
 820  * @flags:      iovma and page property
 821  *
 822  * Allocate @bytes linearly and creates 1-1-1 mapping and returns
 823  * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
 824  */
 825 u32 iommu_kmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 826 {
 827         void *va;
 828         u32 pa;
 829
 830         if (!obj || !obj->dev || !bytes)
 831                 return -EINVAL;
 832
 833         bytes = PAGE_ALIGN(bytes);
 834
 835         va = kmalloc(bytes, GFP_KERNEL | GFP_DMA);
 836         if (!va)
 837                 return -ENOMEM;
 838         pa = virt_to_phys(va);
 839
 840         flags &= IOVMF_HW_MASK;
 841         flags |= IOVMF_LINEAR;
 842         flags |= IOVMF_ALLOC;
 843         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 844
 845         da = __iommu_kmap(obj, da, pa, va, bytes, flags);
 846         if (IS_ERR_VALUE(da))
 847                 kfree(va);
 848
 849         return da;
 850 }
 851 EXPORT_SYMBOL_GPL(iommu_kmalloc);
 852
 853 /**
 854  * iommu_kfree  -  release virtual mapping obtained by 'iommu_kmalloc()'
 855  * @obj:        objective iommu
 856  * @da:         iommu device virtual address
 857  *
 858  * Frees the iommu virtually contiguous memory area starting at
 859  * @da, which was passed to and was returned by'iommu_kmalloc()'.
 860  */
 861 void iommu_kfree(struct iommu *obj, u32 da)
 862 {
 863         struct sg_table *sgt;
 864
 865         sgt = unmap_vm_area(obj, da, kfree, IOVMF_LINEAR | IOVMF_ALLOC);
 866         if (!sgt)
 867                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 868         sgtable_free(sgt);
 869 }
 870 EXPORT_SYMBOL_GPL(iommu_kfree);
 871
 872
 873 static int __init iovmm_init(void)
 874 {
 875         const unsigned long flags = SLAB_HWCACHE_ALIGN;
 876         struct kmem_cache *p;
 877
 878         p = kmem_cache_create("iovm_area_cache", sizeof(struct iovm_struct), 0,
 879                               flags, NULL);
 880         if (!p)
 881                 return -ENOMEM;
 882         iovm_area_cachep = p;
 883
 884         return 0;
 885 }
 886 module_init(iovmm_init);
 887
 888 static void __exit iovmm_exit(void)
 889 {
 890         kmem_cache_destroy(iovm_area_cachep);
 891 }
 892 module_exit(iovmm_exit);
 893
 894 MODULE_DESCRIPTION("omap iommu: simple virtual address space management");
 895 MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
 896 MODULE_LICENSE("GPL v2");