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