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((unsigned long)new->addr,
 203                                 (unsigned long)(new->addr + total));
 204         return new->addr;
 205
 206 err_out:
 207         WARN_ON(1); /* FIXME: cleanup some mpu mappings */
 208         vunmap(new->addr);
 209         return ERR_PTR(-EAGAIN);
 210 }
 211
 212 static inline void vunmap_sg(const void *va)
 213 {
 214         vunmap(va);
 215 }
 216
 217 static struct iovm_struct *__find_iovm_area(struct iommu *obj, const u32 da)
 218 {
 219         struct iovm_struct *tmp;
 220
 221         list_for_each_entry(tmp, &obj->mmap, list) {
 222                 if ((da >= tmp->da_start) && (da < tmp->da_end)) {
 223                         size_t len;
 224
 225                         len = tmp->da_end - tmp->da_start;
 226
 227                         dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n",
 228                                 __func__, tmp->da_start, da, tmp->da_end, len,
 229                                 tmp->flags);
 230
 231                         return tmp;
 232                 }
 233         }
 234
 235         return NULL;
 236 }
 237
 238 /**
 239  * find_iovm_area  -  find iovma which includes @da
 240  * @da:         iommu device virtual address
 241  *
 242  * Find the existing iovma starting at @da
 243  */
 244 struct iovm_struct *find_iovm_area(struct iommu *obj, u32 da)
 245 {
 246         struct iovm_struct *area;
 247
 248         mutex_lock(&obj->mmap_lock);
 249         area = __find_iovm_area(obj, da);
 250         mutex_unlock(&obj->mmap_lock);
 251
 252         return area;
 253 }
 254 EXPORT_SYMBOL_GPL(find_iovm_area);
 255
 256 /*
 257  * This finds the hole(area) which fits the requested address and len
 258  * in iovmas mmap, and returns the new allocated iovma.
 259  */
 260 static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
 261                                            size_t bytes, u32 flags)
 262 {
 263         struct iovm_struct *new, *tmp;
 264         u32 start, prev_end, alignement;
 265
 266         if (!obj || !bytes)
 267                 return ERR_PTR(-EINVAL);
 268
 269         start = da;
 270         alignement = PAGE_SIZE;
 271
 272         if (flags & IOVMF_DA_ANON) {
 273                 /*
 274                  * Reserve the first page for NULL
 275                  */
 276                 start = PAGE_SIZE;
 277                 if (flags & IOVMF_LINEAR)
 278                         alignement = iopgsz_max(bytes);
 279                 start = roundup(start, alignement);
 280         }
 281
 282         tmp = NULL;
 283         if (list_empty(&obj->mmap))
 284                 goto found;
 285
 286         prev_end = 0;
 287         list_for_each_entry(tmp, &obj->mmap, list) {
 288
 289                 if ((prev_end <= start) && (start + bytes < tmp->da_start))
 290                         goto found;
 291
 292                 if (flags & IOVMF_DA_ANON)
 293                         start = roundup(tmp->da_end, alignement);
 294
 295                 prev_end = tmp->da_end;
 296         }
 297
 298         if ((start >= prev_end) && (ULONG_MAX - start >= bytes))
 299                 goto found;
 300
 301         dev_dbg(obj->dev, "%s: no space to fit %08x(%x) flags: %08x\n",
 302                 __func__, da, bytes, flags);
 303
 304         return ERR_PTR(-EINVAL);
 305
 306 found:
 307         new = kmem_cache_zalloc(iovm_area_cachep, GFP_KERNEL);
 308         if (!new)
 309                 return ERR_PTR(-ENOMEM);
 310
 311         new->iommu = obj;
 312         new->da_start = start;
 313         new->da_end = start + bytes;
 314         new->flags = flags;
 315
 316         /*
 317          * keep ascending order of iovmas
 318          */
 319         if (tmp)
 320                 list_add_tail(&new->list, &tmp->list);
 321         else
 322                 list_add(&new->list, &obj->mmap);
 323
 324         dev_dbg(obj->dev, "%s: found %08x-%08x-%08x(%x) %08x\n",
 325                 __func__, new->da_start, start, new->da_end, bytes, flags);
 326
 327         return new;
 328 }
 329
 330 static void free_iovm_area(struct iommu *obj, struct iovm_struct *area)
 331 {
 332         size_t bytes;
 333
 334         BUG_ON(!obj || !area);
 335
 336         bytes = area->da_end - area->da_start;
 337
 338         dev_dbg(obj->dev, "%s: %08x-%08x(%x) %08x\n",
 339                 __func__, area->da_start, area->da_end, bytes, area->flags);
 340
 341         list_del(&area->list);
 342         kmem_cache_free(iovm_area_cachep, area);
 343 }
 344
 345 /**
 346  * da_to_va - convert (d) to (v)
 347  * @obj:        objective iommu
 348  * @da:         iommu device virtual address
 349  * @va:         mpu virtual address
 350  *
 351  * Returns mpu virtual addr which corresponds to a given device virtual addr
 352  */
 353 void *da_to_va(struct iommu *obj, u32 da)
 354 {
 355         void *va = NULL;
 356         struct iovm_struct *area;
 357
 358         mutex_lock(&obj->mmap_lock);
 359
 360         area = __find_iovm_area(obj, da);
 361         if (!area) {
 362                 dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
 363                 goto out;
 364         }
 365         va = area->va;
 366         mutex_unlock(&obj->mmap_lock);
 367 out:
 368         return va;
 369 }
 370 EXPORT_SYMBOL_GPL(da_to_va);
 371
 372 static void sgtable_fill_vmalloc(struct sg_table *sgt, void *_va)
 373 {
 374         unsigned int i;
 375         struct scatterlist *sg;
 376         void *va = _va;
 377         void *va_end;
 378
 379         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 380                 struct page *pg;
 381                 const size_t bytes = PAGE_SIZE;
 382
 383                 /*
 384                  * iommu 'superpage' isn't supported with 'iommu_vmalloc()'
 385                  */
 386                 pg = vmalloc_to_page(va);
 387                 BUG_ON(!pg);
 388                 sg_set_page(sg, pg, bytes, 0);
 389
 390                 va += bytes;
 391         }
 392
 393         va_end = _va + PAGE_SIZE * i;
 394         flush_cache_vmap((unsigned long)_va, (unsigned long)va_end);
 395 }
 396
 397 static inline void sgtable_drain_vmalloc(struct sg_table *sgt)
 398 {
 399         /*
 400          * Actually this is not necessary at all, just exists for
 401          * consistency of the code readibility.
 402          */
 403         BUG_ON(!sgt);
 404 }
 405
 406 static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, size_t len)
 407 {
 408         unsigned int i;
 409         struct scatterlist *sg;
 410         void *va;
 411
 412         va = phys_to_virt(pa);
 413
 414         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 415                 size_t bytes;
 416
 417                 bytes = iopgsz_max(len);
 418
 419                 BUG_ON(!iopgsz_ok(bytes));
 420
 421                 sg_set_buf(sg, phys_to_virt(pa), bytes);
 422                 /*
 423                  * 'pa' is cotinuous(linear).
 424                  */
 425                 pa += bytes;
 426                 len -= bytes;
 427         }
 428         BUG_ON(len);
 429
 430         clean_dcache_area(va, len);
 431 }
 432
 433 static inline void sgtable_drain_kmalloc(struct sg_table *sgt)
 434 {
 435         /*
 436          * Actually this is not necessary at all, just exists for
 437          * consistency of the code readibility
 438          */
 439         BUG_ON(!sgt);
 440 }
 441
 442 /* create 'da' <-> 'pa' mapping from 'sgt' */
 443 static int map_iovm_area(struct iommu *obj, struct iovm_struct *new,
 444                          const struct sg_table *sgt, u32 flags)
 445 {
 446         int err;
 447         unsigned int i, j;
 448         struct scatterlist *sg;
 449         u32 da = new->da_start;
 450
 451         if (!obj || !new || !sgt)
 452                 return -EINVAL;
 453
 454         BUG_ON(!sgtable_ok(sgt));
 455
 456         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 457                 u32 pa;
 458                 int pgsz;
 459                 size_t bytes;
 460                 struct iotlb_entry e;
 461
 462                 pa = sg_phys(sg);
 463                 bytes = sg_dma_len(sg);
 464
 465                 flags &= ~IOVMF_PGSZ_MASK;
 466                 pgsz = bytes_to_iopgsz(bytes);
 467                 if (pgsz < 0)
 468                         goto err_out;
 469                 flags |= pgsz;
 470
 471                 pr_debug("%s: [%d] %08x %08x(%x)\n", __func__,
 472                          i, da, pa, bytes);
 473
 474                 iotlb_init_entry(&e, da, pa, flags);
 475                 err = iopgtable_store_entry(obj, &e);
 476                 if (err)
 477                         goto err_out;
 478
 479                 da += bytes;
 480         }
 481         return 0;
 482
 483 err_out:
 484         da = new->da_start;
 485
 486         for_each_sg(sgt->sgl, sg, i, j) {
 487                 size_t bytes;
 488
 489                 bytes = iopgtable_clear_entry(obj, da);
 490
 491                 BUG_ON(!iopgsz_ok(bytes));
 492
 493                 da += bytes;
 494         }
 495         return err;
 496 }
 497
 498 /* release 'da' <-> 'pa' mapping */
 499 static void unmap_iovm_area(struct iommu *obj, struct iovm_struct *area)
 500 {
 501         u32 start;
 502         size_t total = area->da_end - area->da_start;
 503
 504         BUG_ON((!total) || !IS_ALIGNED(total, PAGE_SIZE));
 505
 506         start = area->da_start;
 507         while (total > 0) {
 508                 size_t bytes;
 509
 510                 bytes = iopgtable_clear_entry(obj, start);
 511                 if (bytes == 0)
 512                         bytes = PAGE_SIZE;
 513                 else
 514                         dev_dbg(obj->dev, "%s: unmap %08x(%x) %08x\n",
 515                                 __func__, start, bytes, area->flags);
 516
 517                 BUG_ON(!IS_ALIGNED(bytes, PAGE_SIZE));
 518
 519                 total -= bytes;
 520                 start += bytes;
 521         }
 522         BUG_ON(total);
 523 }
 524
 525 /* template function for all unmapping */
 526 static struct sg_table *unmap_vm_area(struct iommu *obj, const u32 da,
 527                                       void (*fn)(const void *), u32 flags)
 528 {
 529         struct sg_table *sgt = NULL;
 530         struct iovm_struct *area;
 531
 532         if (!IS_ALIGNED(da, PAGE_SIZE)) {
 533                 dev_err(obj->dev, "%s: alignment err(%08x)\n", __func__, da);
 534                 return NULL;
 535         }
 536
 537         mutex_lock(&obj->mmap_lock);
 538
 539         area = __find_iovm_area(obj, da);
 540         if (!area) {
 541                 dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
 542                 goto out;
 543         }
 544
 545         if ((area->flags & flags) != flags) {
 546                 dev_err(obj->dev, "%s: wrong flags(%08x)\n", __func__,
 547                         area->flags);
 548                 goto out;
 549         }
 550         sgt = (struct sg_table *)area->sgt;
 551
 552         unmap_iovm_area(obj, area);
 553
 554         fn(area->va);
 555
 556         dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n", __func__,
 557                 area->da_start, da, area->da_end,
 558                 area->da_end - area->da_start, area->flags);
 559
 560         free_iovm_area(obj, area);
 561 out:
 562         mutex_unlock(&obj->mmap_lock);
 563
 564         return sgt;
 565 }
 566
 567 static u32 map_iommu_region(struct iommu *obj, u32 da,
 568               const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
 569 {
 570         int err = -ENOMEM;
 571         struct iovm_struct *new;
 572
 573         mutex_lock(&obj->mmap_lock);
 574
 575         new = alloc_iovm_area(obj, da, bytes, flags);
 576         if (IS_ERR(new)) {
 577                 err = PTR_ERR(new);
 578                 goto err_alloc_iovma;
 579         }
 580         new->va = va;
 581         new->sgt = sgt;
 582
 583         if (map_iovm_area(obj, new, sgt, new->flags))
 584                 goto err_map;
 585
 586         mutex_unlock(&obj->mmap_lock);
 587
 588         dev_dbg(obj->dev, "%s: da:%08x(%x) flags:%08x va:%p\n",
 589                 __func__, new->da_start, bytes, new->flags, va);
 590
 591         return new->da_start;
 592
 593 err_map:
 594         free_iovm_area(obj, new);
 595 err_alloc_iovma:
 596         mutex_unlock(&obj->mmap_lock);
 597         return err;
 598 }
 599
 600 static inline u32 __iommu_vmap(struct iommu *obj, u32 da,
 601                  const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
 602 {
 603         return map_iommu_region(obj, da, sgt, va, bytes, flags);
 604 }
 605
 606 /**
 607  * iommu_vmap  -  (d)-(p)-(v) address mapper
 608  * @obj:        objective iommu
 609  * @sgt:        address of scatter gather table
 610  * @flags:      iovma and page property
 611  *
 612  * Creates 1-n-1 mapping with given @sgt and returns @da.
 613  * All @sgt element must be io page size aligned.
 614  */
 615 u32 iommu_vmap(struct iommu *obj, u32 da, const struct sg_table *sgt,
 616                  u32 flags)
 617 {
 618         size_t bytes;
 619         void *va;
 620
 621         if (!obj || !obj->dev || !sgt)
 622                 return -EINVAL;
 623
 624         bytes = sgtable_len(sgt);
 625         if (!bytes)
 626                 return -EINVAL;
 627         bytes = PAGE_ALIGN(bytes);
 628
 629         va = vmap_sg(sgt);
 630         if (IS_ERR(va))
 631                 return PTR_ERR(va);
 632
 633         flags &= IOVMF_HW_MASK;
 634         flags |= IOVMF_DISCONT;
 635         flags |= IOVMF_MMIO;
 636         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 637
 638         da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
 639         if (IS_ERR_VALUE(da))
 640                 vunmap_sg(va);
 641
 642         return da;
 643 }
 644 EXPORT_SYMBOL_GPL(iommu_vmap);
 645
 646 /**
 647  * iommu_vunmap  -  release virtual mapping obtained by 'iommu_vmap()'
 648  * @obj:        objective iommu
 649  * @da:         iommu device virtual address
 650  *
 651  * Free the iommu virtually contiguous memory area starting at
 652  * @da, which was returned by 'iommu_vmap()'.
 653  */
 654 struct sg_table *iommu_vunmap(struct iommu *obj, u32 da)
 655 {
 656         struct sg_table *sgt;
 657         /*
 658          * 'sgt' is allocated before 'iommu_vmalloc()' is called.
 659          * Just returns 'sgt' to the caller to free
 660          */
 661         sgt = unmap_vm_area(obj, da, vunmap_sg, IOVMF_DISCONT | IOVMF_MMIO);
 662         if (!sgt)
 663                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 664         return sgt;
 665 }
 666 EXPORT_SYMBOL_GPL(iommu_vunmap);
 667
 668 /**
 669  * iommu_vmalloc  -  (d)-(p)-(v) address allocator and mapper
 670  * @obj:        objective iommu
 671  * @da:         contiguous iommu virtual memory
 672  * @bytes:      allocation size
 673  * @flags:      iovma and page property
 674  *
 675  * Allocate @bytes linearly and creates 1-n-1 mapping and returns
 676  * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
 677  */
 678 u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 679 {
 680         void *va;
 681         struct sg_table *sgt;
 682
 683         if (!obj || !obj->dev || !bytes)
 684                 return -EINVAL;
 685
 686         bytes = PAGE_ALIGN(bytes);
 687
 688         va = vmalloc(bytes);
 689         if (!va)
 690                 return -ENOMEM;
 691
 692         sgt = sgtable_alloc(bytes, flags);
 693         if (IS_ERR(sgt)) {
 694                 da = PTR_ERR(sgt);
 695                 goto err_sgt_alloc;
 696         }
 697         sgtable_fill_vmalloc(sgt, va);
 698
 699         flags &= IOVMF_HW_MASK;
 700         flags |= IOVMF_DISCONT;
 701         flags |= IOVMF_ALLOC;
 702         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 703
 704         da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
 705         if (IS_ERR_VALUE(da))
 706                 goto err_iommu_vmap;
 707
 708         return da;
 709
 710 err_iommu_vmap:
 711         sgtable_drain_vmalloc(sgt);
 712         sgtable_free(sgt);
 713 err_sgt_alloc:
 714         vfree(va);
 715         return da;
 716 }
 717 EXPORT_SYMBOL_GPL(iommu_vmalloc);
 718
 719 /**
 720  * iommu_vfree  -  release memory allocated by 'iommu_vmalloc()'
 721  * @obj:        objective iommu
 722  * @da:         iommu device virtual address
 723  *
 724  * Frees the iommu virtually continuous memory area starting at
 725  * @da, as obtained from 'iommu_vmalloc()'.
 726  */
 727 void iommu_vfree(struct iommu *obj, const u32 da)
 728 {
 729         struct sg_table *sgt;
 730
 731         sgt = unmap_vm_area(obj, da, vfree, IOVMF_DISCONT | IOVMF_ALLOC);
 732         if (!sgt)
 733                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 734         sgtable_free(sgt);
 735 }
 736 EXPORT_SYMBOL_GPL(iommu_vfree);
 737
 738 static u32 __iommu_kmap(struct iommu *obj, u32 da, u32 pa, void *va,
 739                           size_t bytes, u32 flags)
 740 {
 741         struct sg_table *sgt;
 742
 743         sgt = sgtable_alloc(bytes, flags);
 744         if (IS_ERR(sgt))
 745                 return PTR_ERR(sgt);
 746
 747         sgtable_fill_kmalloc(sgt, pa, bytes);
 748
 749         da = map_iommu_region(obj, da, sgt, va, bytes, flags);
 750         if (IS_ERR_VALUE(da)) {
 751                 sgtable_drain_kmalloc(sgt);
 752                 sgtable_free(sgt);
 753         }
 754
 755         return da;
 756 }
 757
 758 /**
 759  * iommu_kmap  -  (d)-(p)-(v) address mapper
 760  * @obj:        objective iommu
 761  * @da:         contiguous iommu virtual memory
 762  * @pa:         contiguous physical memory
 763  * @flags:      iovma and page property
 764  *
 765  * Creates 1-1-1 mapping and returns @da again, which can be
 766  * adjusted if 'IOVMF_DA_ANON' is set.
 767  */
 768 u32 iommu_kmap(struct iommu *obj, u32 da, u32 pa, size_t bytes,
 769                  u32 flags)
 770 {
 771         void *va;
 772
 773         if (!obj || !obj->dev || !bytes)
 774                 return -EINVAL;
 775
 776         bytes = PAGE_ALIGN(bytes);
 777
 778         va = ioremap(pa, bytes);
 779         if (!va)
 780                 return -ENOMEM;
 781
 782         flags &= IOVMF_HW_MASK;
 783         flags |= IOVMF_LINEAR;
 784         flags |= IOVMF_MMIO;
 785         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 786
 787         da = __iommu_kmap(obj, da, pa, va, bytes, flags);
 788         if (IS_ERR_VALUE(da))
 789                 iounmap(va);
 790
 791         return da;
 792 }
 793 EXPORT_SYMBOL_GPL(iommu_kmap);
 794
 795 /**
 796  * iommu_kunmap  -  release virtual mapping obtained by 'iommu_kmap()'
 797  * @obj:        objective iommu
 798  * @da:         iommu device virtual address
 799  *
 800  * Frees the iommu virtually contiguous memory area starting at
 801  * @da, which was passed to and was returned by'iommu_kmap()'.
 802  */
 803 void iommu_kunmap(struct iommu *obj, u32 da)
 804 {
 805         struct sg_table *sgt;
 806         typedef void (*func_t)(const void *);
 807
 808         sgt = unmap_vm_area(obj, da, (func_t)__iounmap,
 809                             IOVMF_LINEAR | IOVMF_MMIO);
 810         if (!sgt)
 811                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 812         sgtable_free(sgt);
 813 }
 814 EXPORT_SYMBOL_GPL(iommu_kunmap);
 815
 816 /**
 817  * iommu_kmalloc  -  (d)-(p)-(v) address allocator and mapper
 818  * @obj:        objective iommu
 819  * @da:         contiguous iommu virtual memory
 820  * @bytes:      bytes for allocation
 821  * @flags:      iovma and page property
 822  *
 823  * Allocate @bytes linearly and creates 1-1-1 mapping and returns
 824  * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
 825  */
 826 u32 iommu_kmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 827 {
 828         void *va;
 829         u32 pa;
 830
 831         if (!obj || !obj->dev || !bytes)
 832                 return -EINVAL;
 833
 834         bytes = PAGE_ALIGN(bytes);
 835
 836         va = kmalloc(bytes, GFP_KERNEL | GFP_DMA);
 837         if (!va)
 838                 return -ENOMEM;
 839         pa = virt_to_phys(va);
 840
 841         flags &= IOVMF_HW_MASK;
 842         flags |= IOVMF_LINEAR;
 843         flags |= IOVMF_ALLOC;
 844         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 845
 846         da = __iommu_kmap(obj, da, pa, va, bytes, flags);
 847         if (IS_ERR_VALUE(da))
 848                 kfree(va);
 849
 850         return da;
 851 }
 852 EXPORT_SYMBOL_GPL(iommu_kmalloc);
 853
 854 /**
 855  * iommu_kfree  -  release virtual mapping obtained by 'iommu_kmalloc()'
 856  * @obj:        objective iommu
 857  * @da:         iommu device virtual address
 858  *
 859  * Frees the iommu virtually contiguous memory area starting at
 860  * @da, which was passed to and was returned by'iommu_kmalloc()'.
 861  */
 862 void iommu_kfree(struct iommu *obj, u32 da)
 863 {
 864         struct sg_table *sgt;
 865
 866         sgt = unmap_vm_area(obj, da, kfree, IOVMF_LINEAR | IOVMF_ALLOC);
 867         if (!sgt)
 868                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 869         sgtable_free(sgt);
 870 }
 871 EXPORT_SYMBOL_GPL(iommu_kfree);
 872
 873
 874 static int __init iovmm_init(void)
 875 {
 876         const unsigned long flags = SLAB_HWCACHE_ALIGN;
 877         struct kmem_cache *p;
 878
 879         p = kmem_cache_create("iovm_area_cache", sizeof(struct iovm_struct), 0,
 880                               flags, NULL);
 881         if (!p)
 882                 return -ENOMEM;
 883         iovm_area_cachep = p;
 884
 885         return 0;
 886 }
 887 module_init(iovmm_init);
 888
 889 static void __exit iovmm_exit(void)
 890 {
 891         kmem_cache_destroy(iovm_area_cachep);
 892 }
 893 module_exit(iovmm_exit);
 894
 895 MODULE_DESCRIPTION("omap iommu: simple virtual address space management");
 896 MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
 897 MODULE_LICENSE("GPL v2");