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, alignement;
 275
 276         if (!obj || !bytes)
 277                 return ERR_PTR(-EINVAL);
 278
 279         start = da;
 280         alignement = PAGE_SIZE;
 281
 282         if (flags & IOVMF_DA_ANON) {
 283                 start = obj->da_start;
 284
 285                 if (flags & IOVMF_LINEAR)
 286                         alignement = iopgsz_max(bytes);
 287                 start = roundup(start, alignement);
 288         } else if (start < obj->da_start || start > obj->da_end ||
 289                                         obj->da_end - start < bytes) {
 290                 return ERR_PTR(-EINVAL);
 291         }
 292
 293         tmp = NULL;
 294         if (list_empty(&obj->mmap))
 295                 goto found;
 296
 297         prev_end = 0;
 298         list_for_each_entry(tmp, &obj->mmap, list) {
 299
 300                 if (prev_end > start)
 301                         break;
 302
 303                 if (tmp->da_start > start && (tmp->da_start - start) >= bytes)
 304                         goto found;
 305
 306                 if (tmp->da_end >= start && flags & IOVMF_DA_ANON)
 307                         start = roundup(tmp->da_end + 1, alignement);
 308
 309                 prev_end = tmp->da_end;
 310         }
 311
 312         if ((start >= prev_end) && (obj->da_end - start >= bytes))
 313                 goto found;
 314
 315         dev_dbg(obj->dev, "%s: no space to fit %08x(%x) flags: %08x\n",
 316                 __func__, da, bytes, flags);
 317
 318         return ERR_PTR(-EINVAL);
 319
 320 found:
 321         new = kmem_cache_zalloc(iovm_area_cachep, GFP_KERNEL);
 322         if (!new)
 323                 return ERR_PTR(-ENOMEM);
 324
 325         new->iommu = obj;
 326         new->da_start = start;
 327         new->da_end = start + bytes;
 328         new->flags = flags;
 329
 330         /*
 331          * keep ascending order of iovmas
 332          */
 333         if (tmp)
 334                 list_add_tail(&new->list, &tmp->list);
 335         else
 336                 list_add(&new->list, &obj->mmap);
 337
 338         dev_dbg(obj->dev, "%s: found %08x-%08x-%08x(%x) %08x\n",
 339                 __func__, new->da_start, start, new->da_end, bytes, flags);
 340
 341         return new;
 342 }
 343
 344 static void free_iovm_area(struct iommu *obj, struct iovm_struct *area)
 345 {
 346         size_t bytes;
 347
 348         BUG_ON(!obj || !area);
 349
 350         bytes = area->da_end - area->da_start;
 351
 352         dev_dbg(obj->dev, "%s: %08x-%08x(%x) %08x\n",
 353                 __func__, area->da_start, area->da_end, bytes, area->flags);
 354
 355         list_del(&area->list);
 356         kmem_cache_free(iovm_area_cachep, area);
 357 }
 358
 359 /**
 360  * da_to_va - convert (d) to (v)
 361  * @obj:        objective iommu
 362  * @da:         iommu device virtual address
 363  * @va:         mpu virtual address
 364  *
 365  * Returns mpu virtual addr which corresponds to a given device virtual addr
 366  */
 367 void *da_to_va(struct iommu *obj, u32 da)
 368 {
 369         void *va = NULL;
 370         struct iovm_struct *area;
 371
 372         mutex_lock(&obj->mmap_lock);
 373
 374         area = __find_iovm_area(obj, da);
 375         if (!area) {
 376                 dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
 377                 goto out;
 378         }
 379         va = area->va;
 380 out:
 381         mutex_unlock(&obj->mmap_lock);
 382
 383         return va;
 384 }
 385 EXPORT_SYMBOL_GPL(da_to_va);
 386
 387 static void sgtable_fill_vmalloc(struct sg_table *sgt, void *_va)
 388 {
 389         unsigned int i;
 390         struct scatterlist *sg;
 391         void *va = _va;
 392         void *va_end;
 393
 394         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 395                 struct page *pg;
 396                 const size_t bytes = PAGE_SIZE;
 397
 398                 /*
 399                  * iommu 'superpage' isn't supported with 'iommu_vmalloc()'
 400                  */
 401                 pg = vmalloc_to_page(va);
 402                 BUG_ON(!pg);
 403                 sg_set_page(sg, pg, bytes, 0);
 404
 405                 va += bytes;
 406         }
 407
 408         va_end = _va + PAGE_SIZE * i;
 409 }
 410
 411 static inline void sgtable_drain_vmalloc(struct sg_table *sgt)
 412 {
 413         /*
 414          * Actually this is not necessary at all, just exists for
 415          * consistency of the code readability.
 416          */
 417         BUG_ON(!sgt);
 418 }
 419
 420 static void sgtable_fill_kmalloc(struct sg_table *sgt, u32 pa, u32 da,
 421                                                                 size_t len)
 422 {
 423         unsigned int i;
 424         struct scatterlist *sg;
 425         void *va;
 426
 427         va = phys_to_virt(pa);
 428
 429         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 430                 unsigned bytes;
 431
 432                 bytes = max_alignment(da | pa);
 433                 bytes = min_t(unsigned, bytes, iopgsz_max(len));
 434
 435                 BUG_ON(!iopgsz_ok(bytes));
 436
 437                 sg_set_buf(sg, phys_to_virt(pa), bytes);
 438                 /*
 439                  * 'pa' is cotinuous(linear).
 440                  */
 441                 pa += bytes;
 442                 da += bytes;
 443                 len -= bytes;
 444         }
 445         BUG_ON(len);
 446 }
 447
 448 static inline void sgtable_drain_kmalloc(struct sg_table *sgt)
 449 {
 450         /*
 451          * Actually this is not necessary at all, just exists for
 452          * consistency of the code readability
 453          */
 454         BUG_ON(!sgt);
 455 }
 456
 457 /* create 'da' <-> 'pa' mapping from 'sgt' */
 458 static int map_iovm_area(struct iommu *obj, struct iovm_struct *new,
 459                          const struct sg_table *sgt, u32 flags)
 460 {
 461         int err;
 462         unsigned int i, j;
 463         struct scatterlist *sg;
 464         u32 da = new->da_start;
 465
 466         if (!obj || !sgt)
 467                 return -EINVAL;
 468
 469         BUG_ON(!sgtable_ok(sgt));
 470
 471         for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 472                 u32 pa;
 473                 int pgsz;
 474                 size_t bytes;
 475                 struct iotlb_entry e;
 476
 477                 pa = sg_phys(sg);
 478                 bytes = sg_dma_len(sg);
 479
 480                 flags &= ~IOVMF_PGSZ_MASK;
 481                 pgsz = bytes_to_iopgsz(bytes);
 482                 if (pgsz < 0)
 483                         goto err_out;
 484                 flags |= pgsz;
 485
 486                 pr_debug("%s: [%d] %08x %08x(%x)\n", __func__,
 487                          i, da, pa, bytes);
 488
 489                 iotlb_init_entry(&e, da, pa, flags);
 490                 err = iopgtable_store_entry(obj, &e);
 491                 if (err)
 492                         goto err_out;
 493
 494                 da += bytes;
 495         }
 496         return 0;
 497
 498 err_out:
 499         da = new->da_start;
 500
 501         for_each_sg(sgt->sgl, sg, i, j) {
 502                 size_t bytes;
 503
 504                 bytes = iopgtable_clear_entry(obj, da);
 505
 506                 BUG_ON(!iopgsz_ok(bytes));
 507
 508                 da += bytes;
 509         }
 510         return err;
 511 }
 512
 513 /* release 'da' <-> 'pa' mapping */
 514 static void unmap_iovm_area(struct iommu *obj, struct iovm_struct *area)
 515 {
 516         u32 start;
 517         size_t total = area->da_end - area->da_start;
 518
 519         BUG_ON((!total) || !IS_ALIGNED(total, PAGE_SIZE));
 520
 521         start = area->da_start;
 522         while (total > 0) {
 523                 size_t bytes;
 524
 525                 bytes = iopgtable_clear_entry(obj, start);
 526                 if (bytes == 0)
 527                         bytes = PAGE_SIZE;
 528                 else
 529                         dev_dbg(obj->dev, "%s: unmap %08x(%x) %08x\n",
 530                                 __func__, start, bytes, area->flags);
 531
 532                 BUG_ON(!IS_ALIGNED(bytes, PAGE_SIZE));
 533
 534                 total -= bytes;
 535                 start += bytes;
 536         }
 537         BUG_ON(total);
 538 }
 539
 540 /* template function for all unmapping */
 541 static struct sg_table *unmap_vm_area(struct iommu *obj, const u32 da,
 542                                       void (*fn)(const void *), u32 flags)
 543 {
 544         struct sg_table *sgt = NULL;
 545         struct iovm_struct *area;
 546
 547         if (!IS_ALIGNED(da, PAGE_SIZE)) {
 548                 dev_err(obj->dev, "%s: alignment err(%08x)\n", __func__, da);
 549                 return NULL;
 550         }
 551
 552         mutex_lock(&obj->mmap_lock);
 553
 554         area = __find_iovm_area(obj, da);
 555         if (!area) {
 556                 dev_dbg(obj->dev, "%s: no da area(%08x)\n", __func__, da);
 557                 goto out;
 558         }
 559
 560         if ((area->flags & flags) != flags) {
 561                 dev_err(obj->dev, "%s: wrong flags(%08x)\n", __func__,
 562                         area->flags);
 563                 goto out;
 564         }
 565         sgt = (struct sg_table *)area->sgt;
 566
 567         unmap_iovm_area(obj, area);
 568
 569         fn(area->va);
 570
 571         dev_dbg(obj->dev, "%s: %08x-%08x-%08x(%x) %08x\n", __func__,
 572                 area->da_start, da, area->da_end,
 573                 area->da_end - area->da_start, area->flags);
 574
 575         free_iovm_area(obj, area);
 576 out:
 577         mutex_unlock(&obj->mmap_lock);
 578
 579         return sgt;
 580 }
 581
 582 static u32 map_iommu_region(struct iommu *obj, u32 da,
 583               const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
 584 {
 585         int err = -ENOMEM;
 586         struct iovm_struct *new;
 587
 588         mutex_lock(&obj->mmap_lock);
 589
 590         new = alloc_iovm_area(obj, da, bytes, flags);
 591         if (IS_ERR(new)) {
 592                 err = PTR_ERR(new);
 593                 goto err_alloc_iovma;
 594         }
 595         new->va = va;
 596         new->sgt = sgt;
 597
 598         if (map_iovm_area(obj, new, sgt, new->flags))
 599                 goto err_map;
 600
 601         mutex_unlock(&obj->mmap_lock);
 602
 603         dev_dbg(obj->dev, "%s: da:%08x(%x) flags:%08x va:%p\n",
 604                 __func__, new->da_start, bytes, new->flags, va);
 605
 606         return new->da_start;
 607
 608 err_map:
 609         free_iovm_area(obj, new);
 610 err_alloc_iovma:
 611         mutex_unlock(&obj->mmap_lock);
 612         return err;
 613 }
 614
 615 static inline u32 __iommu_vmap(struct iommu *obj, u32 da,
 616                  const struct sg_table *sgt, void *va, size_t bytes, u32 flags)
 617 {
 618         return map_iommu_region(obj, da, sgt, va, bytes, flags);
 619 }
 620
 621 /**
 622  * iommu_vmap  -  (d)-(p)-(v) address mapper
 623  * @obj:        objective iommu
 624  * @sgt:        address of scatter gather table
 625  * @flags:      iovma and page property
 626  *
 627  * Creates 1-n-1 mapping with given @sgt and returns @da.
 628  * All @sgt element must be io page size aligned.
 629  */
 630 u32 iommu_vmap(struct iommu *obj, u32 da, const struct sg_table *sgt,
 631                  u32 flags)
 632 {
 633         size_t bytes;
 634         void *va = NULL;
 635
 636         if (!obj || !obj->dev || !sgt)
 637                 return -EINVAL;
 638
 639         bytes = sgtable_len(sgt);
 640         if (!bytes)
 641                 return -EINVAL;
 642         bytes = PAGE_ALIGN(bytes);
 643
 644         if (flags & IOVMF_MMIO) {
 645                 va = vmap_sg(sgt);
 646                 if (IS_ERR(va))
 647                         return PTR_ERR(va);
 648         }
 649
 650         flags &= IOVMF_HW_MASK;
 651         flags |= IOVMF_DISCONT;
 652         flags |= IOVMF_MMIO;
 653         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 654
 655         da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
 656         if (IS_ERR_VALUE(da))
 657                 vunmap_sg(va);
 658
 659         return da;
 660 }
 661 EXPORT_SYMBOL_GPL(iommu_vmap);
 662
 663 /**
 664  * iommu_vunmap  -  release virtual mapping obtained by 'iommu_vmap()'
 665  * @obj:        objective iommu
 666  * @da:         iommu device virtual address
 667  *
 668  * Free the iommu virtually contiguous memory area starting at
 669  * @da, which was returned by 'iommu_vmap()'.
 670  */
 671 struct sg_table *iommu_vunmap(struct iommu *obj, u32 da)
 672 {
 673         struct sg_table *sgt;
 674         /*
 675          * 'sgt' is allocated before 'iommu_vmalloc()' is called.
 676          * Just returns 'sgt' to the caller to free
 677          */
 678         sgt = unmap_vm_area(obj, da, vunmap_sg, IOVMF_DISCONT | IOVMF_MMIO);
 679         if (!sgt)
 680                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 681         return sgt;
 682 }
 683 EXPORT_SYMBOL_GPL(iommu_vunmap);
 684
 685 /**
 686  * iommu_vmalloc  -  (d)-(p)-(v) address allocator and mapper
 687  * @obj:        objective iommu
 688  * @da:         contiguous iommu virtual memory
 689  * @bytes:      allocation size
 690  * @flags:      iovma and page property
 691  *
 692  * Allocate @bytes linearly and creates 1-n-1 mapping and returns
 693  * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
 694  */
 695 u32 iommu_vmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 696 {
 697         void *va;
 698         struct sg_table *sgt;
 699
 700         if (!obj || !obj->dev || !bytes)
 701                 return -EINVAL;
 702
 703         bytes = PAGE_ALIGN(bytes);
 704
 705         va = vmalloc(bytes);
 706         if (!va)
 707                 return -ENOMEM;
 708
 709         flags &= IOVMF_HW_MASK;
 710         flags |= IOVMF_DISCONT;
 711         flags |= IOVMF_ALLOC;
 712         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 713
 714         sgt = sgtable_alloc(bytes, flags, da, 0);
 715         if (IS_ERR(sgt)) {
 716                 da = PTR_ERR(sgt);
 717                 goto err_sgt_alloc;
 718         }
 719         sgtable_fill_vmalloc(sgt, va);
 720
 721         da = __iommu_vmap(obj, da, sgt, va, bytes, flags);
 722         if (IS_ERR_VALUE(da))
 723                 goto err_iommu_vmap;
 724
 725         return da;
 726
 727 err_iommu_vmap:
 728         sgtable_drain_vmalloc(sgt);
 729         sgtable_free(sgt);
 730 err_sgt_alloc:
 731         vfree(va);
 732         return da;
 733 }
 734 EXPORT_SYMBOL_GPL(iommu_vmalloc);
 735
 736 /**
 737  * iommu_vfree  -  release memory allocated by 'iommu_vmalloc()'
 738  * @obj:        objective iommu
 739  * @da:         iommu device virtual address
 740  *
 741  * Frees the iommu virtually continuous memory area starting at
 742  * @da, as obtained from 'iommu_vmalloc()'.
 743  */
 744 void iommu_vfree(struct iommu *obj, const u32 da)
 745 {
 746         struct sg_table *sgt;
 747
 748         sgt = unmap_vm_area(obj, da, vfree, IOVMF_DISCONT | IOVMF_ALLOC);
 749         if (!sgt)
 750                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 751         sgtable_free(sgt);
 752 }
 753 EXPORT_SYMBOL_GPL(iommu_vfree);
 754
 755 static u32 __iommu_kmap(struct iommu *obj, u32 da, u32 pa, void *va,
 756                           size_t bytes, u32 flags)
 757 {
 758         struct sg_table *sgt;
 759
 760         sgt = sgtable_alloc(bytes, flags, da, pa);
 761         if (IS_ERR(sgt))
 762                 return PTR_ERR(sgt);
 763
 764         sgtable_fill_kmalloc(sgt, pa, da, bytes);
 765
 766         da = map_iommu_region(obj, da, sgt, va, bytes, flags);
 767         if (IS_ERR_VALUE(da)) {
 768                 sgtable_drain_kmalloc(sgt);
 769                 sgtable_free(sgt);
 770         }
 771
 772         return da;
 773 }
 774
 775 /**
 776  * iommu_kmap  -  (d)-(p)-(v) address mapper
 777  * @obj:        objective iommu
 778  * @da:         contiguous iommu virtual memory
 779  * @pa:         contiguous physical memory
 780  * @flags:      iovma and page property
 781  *
 782  * Creates 1-1-1 mapping and returns @da again, which can be
 783  * adjusted if 'IOVMF_DA_ANON' is set.
 784  */
 785 u32 iommu_kmap(struct iommu *obj, u32 da, u32 pa, size_t bytes,
 786                  u32 flags)
 787 {
 788         void *va;
 789
 790         if (!obj || !obj->dev || !bytes)
 791                 return -EINVAL;
 792
 793         bytes = PAGE_ALIGN(bytes);
 794
 795         va = ioremap(pa, bytes);
 796         if (!va)
 797                 return -ENOMEM;
 798
 799         flags &= IOVMF_HW_MASK;
 800         flags |= IOVMF_LINEAR;
 801         flags |= IOVMF_MMIO;
 802         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 803
 804         da = __iommu_kmap(obj, da, pa, va, bytes, flags);
 805         if (IS_ERR_VALUE(da))
 806                 iounmap(va);
 807
 808         return da;
 809 }
 810 EXPORT_SYMBOL_GPL(iommu_kmap);
 811
 812 /**
 813  * iommu_kunmap  -  release virtual mapping obtained by 'iommu_kmap()'
 814  * @obj:        objective iommu
 815  * @da:         iommu device virtual address
 816  *
 817  * Frees the iommu virtually contiguous memory area starting at
 818  * @da, which was passed to and was returned by'iommu_kmap()'.
 819  */
 820 void iommu_kunmap(struct iommu *obj, u32 da)
 821 {
 822         struct sg_table *sgt;
 823         typedef void (*func_t)(const void *);
 824
 825         sgt = unmap_vm_area(obj, da, (func_t)iounmap,
 826                             IOVMF_LINEAR | IOVMF_MMIO);
 827         if (!sgt)
 828                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 829         sgtable_free(sgt);
 830 }
 831 EXPORT_SYMBOL_GPL(iommu_kunmap);
 832
 833 /**
 834  * iommu_kmalloc  -  (d)-(p)-(v) address allocator and mapper
 835  * @obj:        objective iommu
 836  * @da:         contiguous iommu virtual memory
 837  * @bytes:      bytes for allocation
 838  * @flags:      iovma and page property
 839  *
 840  * Allocate @bytes linearly and creates 1-1-1 mapping and returns
 841  * @da again, which might be adjusted if 'IOVMF_DA_ANON' is set.
 842  */
 843 u32 iommu_kmalloc(struct iommu *obj, u32 da, size_t bytes, u32 flags)
 844 {
 845         void *va;
 846         u32 pa;
 847
 848         if (!obj || !obj->dev || !bytes)
 849                 return -EINVAL;
 850
 851         bytes = PAGE_ALIGN(bytes);
 852
 853         va = kmalloc(bytes, GFP_KERNEL | GFP_DMA);
 854         if (!va)
 855                 return -ENOMEM;
 856         pa = virt_to_phys(va);
 857
 858         flags &= IOVMF_HW_MASK;
 859         flags |= IOVMF_LINEAR;
 860         flags |= IOVMF_ALLOC;
 861         flags |= (da ? IOVMF_DA_FIXED : IOVMF_DA_ANON);
 862
 863         da = __iommu_kmap(obj, da, pa, va, bytes, flags);
 864         if (IS_ERR_VALUE(da))
 865                 kfree(va);
 866
 867         return da;
 868 }
 869 EXPORT_SYMBOL_GPL(iommu_kmalloc);
 870
 871 /**
 872  * iommu_kfree  -  release virtual mapping obtained by 'iommu_kmalloc()'
 873  * @obj:        objective iommu
 874  * @da:         iommu device virtual address
 875  *
 876  * Frees the iommu virtually contiguous memory area starting at
 877  * @da, which was passed to and was returned by'iommu_kmalloc()'.
 878  */
 879 void iommu_kfree(struct iommu *obj, u32 da)
 880 {
 881         struct sg_table *sgt;
 882
 883         sgt = unmap_vm_area(obj, da, kfree, IOVMF_LINEAR | IOVMF_ALLOC);
 884         if (!sgt)
 885                 dev_dbg(obj->dev, "%s: No sgt\n", __func__);
 886         sgtable_free(sgt);
 887 }
 888 EXPORT_SYMBOL_GPL(iommu_kfree);
 889
 890
 891 static int __init iovmm_init(void)
 892 {
 893         const unsigned long flags = SLAB_HWCACHE_ALIGN;
 894         struct kmem_cache *p;
 895
 896         p = kmem_cache_create("iovm_area_cache", sizeof(struct iovm_struct), 0,
 897                               flags, NULL);
 898         if (!p)
 899                 return -ENOMEM;
 900         iovm_area_cachep = p;
 901
 902         return 0;
 903 }
 904 module_init(iovmm_init);
 905
 906 static void __exit iovmm_exit(void)
 907 {
 908         kmem_cache_destroy(iovm_area_cachep);
 909 }
 910 module_exit(iovmm_exit);
 911
 912 MODULE_DESCRIPTION("omap iommu: simple virtual address space management");
 913 MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
 914 MODULE_LICENSE("GPL v2");