arch/s390/pci/pci_dma.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright IBM Corp. 2012
   4  *
   5  * Author(s):
   6  *   Jan Glauber <jang@linux.vnet.ibm.com>
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/slab.h>
  11 #include <linux/export.h>
  12 #include <linux/iommu-helper.h>
  13 #include <linux/dma-mapping.h>
  14 #include <linux/vmalloc.h>
  15 #include <linux/pci.h>
  16 #include <asm/pci_dma.h>
  17
  18 #define S390_MAPPING_ERROR              (~(dma_addr_t) 0x0)
  19
  20 static struct kmem_cache *dma_region_table_cache;
  21 static struct kmem_cache *dma_page_table_cache;
  22 static int s390_iommu_strict;
  23
  24 static int zpci_refresh_global(struct zpci_dev *zdev)
  25 {
  26         return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma,
  27                                   zdev->iommu_pages * PAGE_SIZE);
  28 }
  29
  30 unsigned long *dma_alloc_cpu_table(void)
  31 {
  32         unsigned long *table, *entry;
  33
  34         table = kmem_cache_alloc(dma_region_table_cache, GFP_ATOMIC);
  35         if (!table)
  36                 return NULL;
  37
  38         for (entry = table; entry < table + ZPCI_TABLE_ENTRIES; entry++)
  39                 *entry = ZPCI_TABLE_INVALID;
  40         return table;
  41 }
  42
  43 static void dma_free_cpu_table(void *table)
  44 {
  45         kmem_cache_free(dma_region_table_cache, table);
  46 }
  47
  48 static unsigned long *dma_alloc_page_table(void)
  49 {
  50         unsigned long *table, *entry;
  51
  52         table = kmem_cache_alloc(dma_page_table_cache, GFP_ATOMIC);
  53         if (!table)
  54                 return NULL;
  55
  56         for (entry = table; entry < table + ZPCI_PT_ENTRIES; entry++)
  57                 *entry = ZPCI_PTE_INVALID;
  58         return table;
  59 }
  60
  61 static void dma_free_page_table(void *table)
  62 {
  63         kmem_cache_free(dma_page_table_cache, table);
  64 }
  65
  66 static unsigned long *dma_get_seg_table_origin(unsigned long *entry)
  67 {
  68         unsigned long *sto;
  69
  70         if (reg_entry_isvalid(*entry))
  71                 sto = get_rt_sto(*entry);
  72         else {
  73                 sto = dma_alloc_cpu_table();
  74                 if (!sto)
  75                         return NULL;
  76
  77                 set_rt_sto(entry, sto);
  78                 validate_rt_entry(entry);
  79                 entry_clr_protected(entry);
  80         }
  81         return sto;
  82 }
  83
  84 static unsigned long *dma_get_page_table_origin(unsigned long *entry)
  85 {
  86         unsigned long *pto;
  87
  88         if (reg_entry_isvalid(*entry))
  89                 pto = get_st_pto(*entry);
  90         else {
  91                 pto = dma_alloc_page_table();
  92                 if (!pto)
  93                         return NULL;
  94                 set_st_pto(entry, pto);
  95                 validate_st_entry(entry);
  96                 entry_clr_protected(entry);
  97         }
  98         return pto;
  99 }
 100
 101 unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr)
 102 {
 103         unsigned long *sto, *pto;
 104         unsigned int rtx, sx, px;
 105
 106         rtx = calc_rtx(dma_addr);
 107         sto = dma_get_seg_table_origin(&rto[rtx]);
 108         if (!sto)
 109                 return NULL;
 110
 111         sx = calc_sx(dma_addr);
 112         pto = dma_get_page_table_origin(&sto[sx]);
 113         if (!pto)
 114                 return NULL;
 115
 116         px = calc_px(dma_addr);
 117         return &pto[px];
 118 }
 119
 120 void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags)
 121 {
 122         if (flags & ZPCI_PTE_INVALID) {
 123                 invalidate_pt_entry(entry);
 124         } else {
 125                 set_pt_pfaa(entry, page_addr);
 126                 validate_pt_entry(entry);
 127         }
 128
 129         if (flags & ZPCI_TABLE_PROTECTED)
 130                 entry_set_protected(entry);
 131         else
 132                 entry_clr_protected(entry);
 133 }
 134
 135 static int __dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
 136                               dma_addr_t dma_addr, size_t size, int flags)
 137 {
 138         unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 139         u8 *page_addr = (u8 *) (pa & PAGE_MASK);
 140         unsigned long irq_flags;
 141         unsigned long *entry;
 142         int i, rc = 0;
 143
 144         if (!nr_pages)
 145                 return -EINVAL;
 146
 147         spin_lock_irqsave(&zdev->dma_table_lock, irq_flags);
 148         if (!zdev->dma_table) {
 149                 rc = -EINVAL;
 150                 goto out_unlock;
 151         }
 152
 153         for (i = 0; i < nr_pages; i++) {
 154                 entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
 155                 if (!entry) {
 156                         rc = -ENOMEM;
 157                         goto undo_cpu_trans;
 158                 }
 159                 dma_update_cpu_trans(entry, page_addr, flags);
 160                 page_addr += PAGE_SIZE;
 161                 dma_addr += PAGE_SIZE;
 162         }
 163
 164 undo_cpu_trans:
 165         if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) {
 166                 flags = ZPCI_PTE_INVALID;
 167                 while (i-- > 0) {
 168                         page_addr -= PAGE_SIZE;
 169                         dma_addr -= PAGE_SIZE;
 170                         entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr);
 171                         if (!entry)
 172                                 break;
 173                         dma_update_cpu_trans(entry, page_addr, flags);
 174                 }
 175         }
 176 out_unlock:
 177         spin_unlock_irqrestore(&zdev->dma_table_lock, irq_flags);
 178         return rc;
 179 }
 180
 181 static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr,
 182                            size_t size, int flags)
 183 {
 184         unsigned long irqflags;
 185         int ret;
 186
 187         /*
 188          * With zdev->tlb_refresh == 0, rpcit is not required to establish new
 189          * translations when previously invalid translation-table entries are
 190          * validated. With lazy unmap, rpcit is skipped for previously valid
 191          * entries, but a global rpcit is then required before any address can
 192          * be re-used, i.e. after each iommu bitmap wrap-around.
 193          */
 194         if ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID) {
 195                 if (!zdev->tlb_refresh)
 196                         return 0;
 197         } else {
 198                 if (!s390_iommu_strict)
 199                         return 0;
 200         }
 201
 202         ret = zpci_refresh_trans((u64) zdev->fh << 32, dma_addr,
 203                                  PAGE_ALIGN(size));
 204         if (ret == -ENOMEM && !s390_iommu_strict) {
 205                 /* enable the hypervisor to free some resources */
 206                 if (zpci_refresh_global(zdev))
 207                         goto out;
 208
 209                 spin_lock_irqsave(&zdev->iommu_bitmap_lock, irqflags);
 210                 bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap,
 211                               zdev->lazy_bitmap, zdev->iommu_pages);
 212                 bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages);
 213                 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, irqflags);
 214                 ret = 0;
 215         }
 216 out:
 217         return ret;
 218 }
 219
 220 static int dma_update_trans(struct zpci_dev *zdev, unsigned long pa,
 221                             dma_addr_t dma_addr, size_t size, int flags)
 222 {
 223         int rc;
 224
 225         rc = __dma_update_trans(zdev, pa, dma_addr, size, flags);
 226         if (rc)
 227                 return rc;
 228
 229         rc = __dma_purge_tlb(zdev, dma_addr, size, flags);
 230         if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID))
 231                 __dma_update_trans(zdev, pa, dma_addr, size, ZPCI_PTE_INVALID);
 232
 233         return rc;
 234 }
 235
 236 void dma_free_seg_table(unsigned long entry)
 237 {
 238         unsigned long *sto = get_rt_sto(entry);
 239         int sx;
 240
 241         for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++)
 242                 if (reg_entry_isvalid(sto[sx]))
 243                         dma_free_page_table(get_st_pto(sto[sx]));
 244
 245         dma_free_cpu_table(sto);
 246 }
 247
 248 void dma_cleanup_tables(unsigned long *table)
 249 {
 250         int rtx;
 251
 252         if (!table)
 253                 return;
 254
 255         for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++)
 256                 if (reg_entry_isvalid(table[rtx]))
 257                         dma_free_seg_table(table[rtx]);
 258
 259         dma_free_cpu_table(table);
 260 }
 261
 262 static unsigned long __dma_alloc_iommu(struct device *dev,
 263                                        unsigned long start, int size)
 264 {
 265         struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 266         unsigned long boundary_size;
 267
 268         boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
 269                               PAGE_SIZE) >> PAGE_SHIFT;
 270         return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages,
 271                                 start, size, zdev->start_dma >> PAGE_SHIFT,
 272                                 boundary_size, 0);
 273 }
 274
 275 static dma_addr_t dma_alloc_address(struct device *dev, int size)
 276 {
 277         struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 278         unsigned long offset, flags;
 279
 280         spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 281         offset = __dma_alloc_iommu(dev, zdev->next_bit, size);
 282         if (offset == -1) {
 283                 if (!s390_iommu_strict) {
 284                         /* global flush before DMA addresses are reused */
 285                         if (zpci_refresh_global(zdev))
 286                                 goto out_error;
 287
 288                         bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap,
 289                                       zdev->lazy_bitmap, zdev->iommu_pages);
 290                         bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages);
 291                 }
 292                 /* wrap-around */
 293                 offset = __dma_alloc_iommu(dev, 0, size);
 294                 if (offset == -1)
 295                         goto out_error;
 296         }
 297         zdev->next_bit = offset + size;
 298         spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 299
 300         return zdev->start_dma + offset * PAGE_SIZE;
 301
 302 out_error:
 303         spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 304         return S390_MAPPING_ERROR;
 305 }
 306
 307 static void dma_free_address(struct device *dev, dma_addr_t dma_addr, int size)
 308 {
 309         struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 310         unsigned long flags, offset;
 311
 312         offset = (dma_addr - zdev->start_dma) >> PAGE_SHIFT;
 313
 314         spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags);
 315         if (!zdev->iommu_bitmap)
 316                 goto out;
 317
 318         if (s390_iommu_strict)
 319                 bitmap_clear(zdev->iommu_bitmap, offset, size);
 320         else
 321                 bitmap_set(zdev->lazy_bitmap, offset, size);
 322
 323 out:
 324         spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags);
 325 }
 326
 327 static inline void zpci_err_dma(unsigned long rc, unsigned long addr)
 328 {
 329         struct {
 330                 unsigned long rc;
 331                 unsigned long addr;
 332         } __packed data = {rc, addr};
 333
 334         zpci_err_hex(&data, sizeof(data));
 335 }
 336
 337 static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page,
 338                                      unsigned long offset, size_t size,
 339                                      enum dma_data_direction direction,
 340                                      unsigned long attrs)
 341 {
 342         struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 343         unsigned long pa = page_to_phys(page) + offset;
 344         int flags = ZPCI_PTE_VALID;
 345         unsigned long nr_pages;
 346         dma_addr_t dma_addr;
 347         int ret;
 348
 349         /* This rounds up number of pages based on size and offset */
 350         nr_pages = iommu_num_pages(pa, size, PAGE_SIZE);
 351         dma_addr = dma_alloc_address(dev, nr_pages);
 352         if (dma_addr == S390_MAPPING_ERROR) {
 353                 ret = -ENOSPC;
 354                 goto out_err;
 355         }
 356
 357         /* Use rounded up size */
 358         size = nr_pages * PAGE_SIZE;
 359
 360         if (direction == DMA_NONE || direction == DMA_TO_DEVICE)
 361                 flags |= ZPCI_TABLE_PROTECTED;
 362
 363         ret = dma_update_trans(zdev, pa, dma_addr, size, flags);
 364         if (ret)
 365                 goto out_free;
 366
 367         atomic64_add(nr_pages, &zdev->mapped_pages);
 368         return dma_addr + (offset & ~PAGE_MASK);
 369
 370 out_free:
 371         dma_free_address(dev, dma_addr, nr_pages);
 372 out_err:
 373         zpci_err("map error:\n");
 374         zpci_err_dma(ret, pa);
 375         return S390_MAPPING_ERROR;
 376 }
 377
 378 static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr,
 379                                  size_t size, enum dma_data_direction direction,
 380                                  unsigned long attrs)
 381 {
 382         struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 383         int npages, ret;
 384
 385         npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
 386         dma_addr = dma_addr & PAGE_MASK;
 387         ret = dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE,
 388                                ZPCI_PTE_INVALID);
 389         if (ret) {
 390                 zpci_err("unmap error:\n");
 391                 zpci_err_dma(ret, dma_addr);
 392                 return;
 393         }
 394
 395         atomic64_add(npages, &zdev->unmapped_pages);
 396         dma_free_address(dev, dma_addr, npages);
 397 }
 398
 399 static void *s390_dma_alloc(struct device *dev, size_t size,
 400                             dma_addr_t *dma_handle, gfp_t flag,
 401                             unsigned long attrs)
 402 {
 403         struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 404         struct page *page;
 405         unsigned long pa;
 406         dma_addr_t map;
 407
 408         size = PAGE_ALIGN(size);
 409         page = alloc_pages(flag, get_order(size));
 410         if (!page)
 411                 return NULL;
 412
 413         pa = page_to_phys(page);
 414         map = s390_dma_map_pages(dev, page, 0, size, DMA_BIDIRECTIONAL, 0);
 415         if (dma_mapping_error(dev, map)) {
 416                 free_pages(pa, get_order(size));
 417                 return NULL;
 418         }
 419
 420         atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages);
 421         if (dma_handle)
 422                 *dma_handle = map;
 423         return (void *) pa;
 424 }
 425
 426 static void s390_dma_free(struct device *dev, size_t size,
 427                           void *pa, dma_addr_t dma_handle,
 428                           unsigned long attrs)
 429 {
 430         struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 431
 432         size = PAGE_ALIGN(size);
 433         atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages);
 434         s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, 0);
 435         free_pages((unsigned long) pa, get_order(size));
 436 }
 437
 438 /* Map a segment into a contiguous dma address area */
 439 static int __s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
 440                              size_t size, dma_addr_t *handle,
 441                              enum dma_data_direction dir)
 442 {
 443         unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 444         struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 445         dma_addr_t dma_addr_base, dma_addr;
 446         int flags = ZPCI_PTE_VALID;
 447         struct scatterlist *s;
 448         unsigned long pa = 0;
 449         int ret;
 450
 451         dma_addr_base = dma_alloc_address(dev, nr_pages);
 452         if (dma_addr_base == S390_MAPPING_ERROR)
 453                 return -ENOMEM;
 454
 455         dma_addr = dma_addr_base;
 456         if (dir == DMA_NONE || dir == DMA_TO_DEVICE)
 457                 flags |= ZPCI_TABLE_PROTECTED;
 458
 459         for (s = sg; dma_addr < dma_addr_base + size; s = sg_next(s)) {
 460                 pa = page_to_phys(sg_page(s));
 461                 ret = __dma_update_trans(zdev, pa, dma_addr,
 462                                          s->offset + s->length, flags);
 463                 if (ret)
 464                         goto unmap;
 465
 466                 dma_addr += s->offset + s->length;
 467         }
 468         ret = __dma_purge_tlb(zdev, dma_addr_base, size, flags);
 469         if (ret)
 470                 goto unmap;
 471
 472         *handle = dma_addr_base;
 473         atomic64_add(nr_pages, &zdev->mapped_pages);
 474
 475         return ret;
 476
 477 unmap:
 478         dma_update_trans(zdev, 0, dma_addr_base, dma_addr - dma_addr_base,
 479                          ZPCI_PTE_INVALID);
 480         dma_free_address(dev, dma_addr_base, nr_pages);
 481         zpci_err("map error:\n");
 482         zpci_err_dma(ret, pa);
 483         return ret;
 484 }
 485
 486 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
 487                            int nr_elements, enum dma_data_direction dir,
 488                            unsigned long attrs)
 489 {
 490         struct scatterlist *s = sg, *start = sg, *dma = sg;
 491         unsigned int max = dma_get_max_seg_size(dev);
 492         unsigned int size = s->offset + s->length;
 493         unsigned int offset = s->offset;
 494         int count = 0, i;
 495
 496         for (i = 1; i < nr_elements; i++) {
 497                 s = sg_next(s);
 498
 499                 s->dma_address = S390_MAPPING_ERROR;
 500                 s->dma_length = 0;
 501
 502                 if (s->offset || (size & ~PAGE_MASK) ||
 503                     size + s->length > max) {
 504                         if (__s390_dma_map_sg(dev, start, size,
 505                                               &dma->dma_address, dir))
 506                                 goto unmap;
 507
 508                         dma->dma_address += offset;
 509                         dma->dma_length = size - offset;
 510
 511                         size = offset = s->offset;
 512                         start = s;
 513                         dma = sg_next(dma);
 514                         count++;
 515                 }
 516                 size += s->length;
 517         }
 518         if (__s390_dma_map_sg(dev, start, size, &dma->dma_address, dir))
 519                 goto unmap;
 520
 521         dma->dma_address += offset;
 522         dma->dma_length = size - offset;
 523
 524         return count + 1;
 525 unmap:
 526         for_each_sg(sg, s, count, i)
 527                 s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s),
 528                                      dir, attrs);
 529
 530         return 0;
 531 }
 532
 533 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 534                               int nr_elements, enum dma_data_direction dir,
 535                               unsigned long attrs)
 536 {
 537         struct scatterlist *s;
 538         int i;
 539
 540         for_each_sg(sg, s, nr_elements, i) {
 541                 if (s->dma_length)
 542                         s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
 543                                              dir, attrs);
 544                 s->dma_address = 0;
 545                 s->dma_length = 0;
 546         }
 547 }
 548
 549 static int s390_mapping_error(struct device *dev, dma_addr_t dma_addr)
 550 {
 551         return dma_addr == S390_MAPPING_ERROR;
 552 }
 553
 554 int zpci_dma_init_device(struct zpci_dev *zdev)
 555 {
 556         int rc;
 557
 558         /*
 559          * At this point, if the device is part of an IOMMU domain, this would
 560          * be a strong hint towards a bug in the IOMMU API (common) code and/or
 561          * simultaneous access via IOMMU and DMA API. So let's issue a warning.
 562          */
 563         WARN_ON(zdev->s390_domain);
 564
 565         spin_lock_init(&zdev->iommu_bitmap_lock);
 566         spin_lock_init(&zdev->dma_table_lock);
 567
 568         zdev->dma_table = dma_alloc_cpu_table();
 569         if (!zdev->dma_table) {
 570                 rc = -ENOMEM;
 571                 goto out;
 572         }
 573
 574         /*
 575          * Restrict the iommu bitmap size to the minimum of the following:
 576          * - main memory size
 577          * - 3-level pagetable address limit minus start_dma offset
 578          * - DMA address range allowed by the hardware (clp query pci fn)
 579          *
 580          * Also set zdev->end_dma to the actual end address of the usable
 581          * range, instead of the theoretical maximum as reported by hardware.
 582          */
 583         zdev->start_dma = PAGE_ALIGN(zdev->start_dma);
 584         zdev->iommu_size = min3((u64) high_memory,
 585                                 ZPCI_TABLE_SIZE_RT - zdev->start_dma,
 586                                 zdev->end_dma - zdev->start_dma + 1);
 587         zdev->end_dma = zdev->start_dma + zdev->iommu_size - 1;
 588         zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
 589         zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
 590         if (!zdev->iommu_bitmap) {
 591                 rc = -ENOMEM;
 592                 goto free_dma_table;
 593         }
 594         if (!s390_iommu_strict) {
 595                 zdev->lazy_bitmap = vzalloc(zdev->iommu_pages / 8);
 596                 if (!zdev->lazy_bitmap) {
 597                         rc = -ENOMEM;
 598                         goto free_bitmap;
 599                 }
 600
 601         }
 602         rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
 603                                 (u64) zdev->dma_table);
 604         if (rc)
 605                 goto free_bitmap;
 606
 607         return 0;
 608 free_bitmap:
 609         vfree(zdev->iommu_bitmap);
 610         zdev->iommu_bitmap = NULL;
 611         vfree(zdev->lazy_bitmap);
 612         zdev->lazy_bitmap = NULL;
 613 free_dma_table:
 614         dma_free_cpu_table(zdev->dma_table);
 615         zdev->dma_table = NULL;
 616 out:
 617         return rc;
 618 }
 619
 620 void zpci_dma_exit_device(struct zpci_dev *zdev)
 621 {
 622         /*
 623          * At this point, if the device is part of an IOMMU domain, this would
 624          * be a strong hint towards a bug in the IOMMU API (common) code and/or
 625          * simultaneous access via IOMMU and DMA API. So let's issue a warning.
 626          */
 627         WARN_ON(zdev->s390_domain);
 628
 629         if (zpci_unregister_ioat(zdev, 0))
 630                 return;
 631
 632         dma_cleanup_tables(zdev->dma_table);
 633         zdev->dma_table = NULL;
 634         vfree(zdev->iommu_bitmap);
 635         zdev->iommu_bitmap = NULL;
 636         vfree(zdev->lazy_bitmap);
 637         zdev->lazy_bitmap = NULL;
 638
 639         zdev->next_bit = 0;
 640 }
 641
 642 static int __init dma_alloc_cpu_table_caches(void)
 643 {
 644         dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables",
 645                                         ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN,
 646                                         0, NULL);
 647         if (!dma_region_table_cache)
 648                 return -ENOMEM;
 649
 650         dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables",
 651                                         ZPCI_PT_SIZE, ZPCI_PT_ALIGN,
 652                                         0, NULL);
 653         if (!dma_page_table_cache) {
 654                 kmem_cache_destroy(dma_region_table_cache);
 655                 return -ENOMEM;
 656         }
 657         return 0;
 658 }
 659
 660 int __init zpci_dma_init(void)
 661 {
 662         return dma_alloc_cpu_table_caches();
 663 }
 664
 665 void zpci_dma_exit(void)
 666 {
 667         kmem_cache_destroy(dma_page_table_cache);
 668         kmem_cache_destroy(dma_region_table_cache);
 669 }
 670
 671 const struct dma_map_ops s390_pci_dma_ops = {
 672         .alloc          = s390_dma_alloc,
 673         .free           = s390_dma_free,
 674         .map_sg         = s390_dma_map_sg,
 675         .unmap_sg       = s390_dma_unmap_sg,
 676         .map_page       = s390_dma_map_pages,
 677         .unmap_page     = s390_dma_unmap_pages,
 678         .mapping_error  = s390_mapping_error,
 679         /* dma_supported is unconditionally true without a callback */
 680 };
 681 EXPORT_SYMBOL_GPL(s390_pci_dma_ops);
 682
 683 static int __init s390_iommu_setup(char *str)
 684 {
 685         if (!strncmp(str, "strict", 6))
 686                 s390_iommu_strict = 1;
 687         return 0;
 688 }
 689
 690 __setup("s390_iommu=", s390_iommu_setup);