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 static u64 s390_iommu_aperture; 22 static u32 s390_iommu_aperture_factor = 1; 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, virt_to_phys(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, virt_to_phys(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, phys_addr_t 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, phys_addr_t pa, 136 dma_addr_t dma_addr, size_t size, int flags) 137 { 138 unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; 139 phys_addr_t page_addr = (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, phys_addr_t 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)); 266 267 return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages, 268 start, size, zdev->start_dma >> PAGE_SHIFT, 269 dma_get_seg_boundary_nr_pages(dev, PAGE_SHIFT), 270 0); 271 } 272 273 static dma_addr_t dma_alloc_address(struct device *dev, int size) 274 { 275 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 276 unsigned long offset, flags; 277 278 spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags); 279 offset = __dma_alloc_iommu(dev, zdev->next_bit, size); 280 if (offset == -1) { 281 if (!s390_iommu_strict) { 282 /* global flush before DMA addresses are reused */ 283 if (zpci_refresh_global(zdev)) 284 goto out_error; 285 286 bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap, 287 zdev->lazy_bitmap, zdev->iommu_pages); 288 bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages); 289 } 290 /* wrap-around */ 291 offset = __dma_alloc_iommu(dev, 0, size); 292 if (offset == -1) 293 goto out_error; 294 } 295 zdev->next_bit = offset + size; 296 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); 297 298 return zdev->start_dma + offset * PAGE_SIZE; 299 300 out_error: 301 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); 302 return DMA_MAPPING_ERROR; 303 } 304 305 static void dma_free_address(struct device *dev, dma_addr_t dma_addr, int size) 306 { 307 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 308 unsigned long flags, offset; 309 310 offset = (dma_addr - zdev->start_dma) >> PAGE_SHIFT; 311 312 spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags); 313 if (!zdev->iommu_bitmap) 314 goto out; 315 316 if (s390_iommu_strict) 317 bitmap_clear(zdev->iommu_bitmap, offset, size); 318 else 319 bitmap_set(zdev->lazy_bitmap, offset, size); 320 321 out: 322 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); 323 } 324 325 static inline void zpci_err_dma(unsigned long rc, unsigned long addr) 326 { 327 struct { 328 unsigned long rc; 329 unsigned long addr; 330 } __packed data = {rc, addr}; 331 332 zpci_err_hex(&data, sizeof(data)); 333 } 334 335 static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page, 336 unsigned long offset, size_t size, 337 enum dma_data_direction direction, 338 unsigned long attrs) 339 { 340 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 341 unsigned long pa = page_to_phys(page) + offset; 342 int flags = ZPCI_PTE_VALID; 343 unsigned long nr_pages; 344 dma_addr_t dma_addr; 345 int ret; 346 347 /* This rounds up number of pages based on size and offset */ 348 nr_pages = iommu_num_pages(pa, size, PAGE_SIZE); 349 dma_addr = dma_alloc_address(dev, nr_pages); 350 if (dma_addr == DMA_MAPPING_ERROR) { 351 ret = -ENOSPC; 352 goto out_err; 353 } 354 355 /* Use rounded up size */ 356 size = nr_pages * PAGE_SIZE; 357 358 if (direction == DMA_NONE || direction == DMA_TO_DEVICE) 359 flags |= ZPCI_TABLE_PROTECTED; 360 361 ret = dma_update_trans(zdev, pa, dma_addr, size, flags); 362 if (ret) 363 goto out_free; 364 365 atomic64_add(nr_pages, &zdev->mapped_pages); 366 return dma_addr + (offset & ~PAGE_MASK); 367 368 out_free: 369 dma_free_address(dev, dma_addr, nr_pages); 370 out_err: 371 zpci_err("map error:\n"); 372 zpci_err_dma(ret, pa); 373 return DMA_MAPPING_ERROR; 374 } 375 376 static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr, 377 size_t size, enum dma_data_direction direction, 378 unsigned long attrs) 379 { 380 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 381 int npages, ret; 382 383 npages = iommu_num_pages(dma_addr, size, PAGE_SIZE); 384 dma_addr = dma_addr & PAGE_MASK; 385 ret = dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE, 386 ZPCI_PTE_INVALID); 387 if (ret) { 388 zpci_err("unmap error:\n"); 389 zpci_err_dma(ret, dma_addr); 390 return; 391 } 392 393 atomic64_add(npages, &zdev->unmapped_pages); 394 dma_free_address(dev, dma_addr, npages); 395 } 396 397 static void *s390_dma_alloc(struct device *dev, size_t size, 398 dma_addr_t *dma_handle, gfp_t flag, 399 unsigned long attrs) 400 { 401 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 402 struct page *page; 403 phys_addr_t pa; 404 dma_addr_t map; 405 406 size = PAGE_ALIGN(size); 407 page = alloc_pages(flag | __GFP_ZERO, get_order(size)); 408 if (!page) 409 return NULL; 410 411 pa = page_to_phys(page); 412 map = s390_dma_map_pages(dev, page, 0, size, DMA_BIDIRECTIONAL, 0); 413 if (dma_mapping_error(dev, map)) { 414 __free_pages(page, get_order(size)); 415 return NULL; 416 } 417 418 atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages); 419 if (dma_handle) 420 *dma_handle = map; 421 return phys_to_virt(pa); 422 } 423 424 static void s390_dma_free(struct device *dev, size_t size, 425 void *vaddr, dma_addr_t dma_handle, 426 unsigned long attrs) 427 { 428 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 429 430 size = PAGE_ALIGN(size); 431 atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages); 432 s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, 0); 433 free_pages((unsigned long)vaddr, get_order(size)); 434 } 435 436 /* Map a segment into a contiguous dma address area */ 437 static int __s390_dma_map_sg(struct device *dev, struct scatterlist *sg, 438 size_t size, dma_addr_t *handle, 439 enum dma_data_direction dir) 440 { 441 unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; 442 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 443 dma_addr_t dma_addr_base, dma_addr; 444 int flags = ZPCI_PTE_VALID; 445 struct scatterlist *s; 446 phys_addr_t pa = 0; 447 int ret; 448 449 dma_addr_base = dma_alloc_address(dev, nr_pages); 450 if (dma_addr_base == DMA_MAPPING_ERROR) 451 return -ENOMEM; 452 453 dma_addr = dma_addr_base; 454 if (dir == DMA_NONE || dir == DMA_TO_DEVICE) 455 flags |= ZPCI_TABLE_PROTECTED; 456 457 for (s = sg; dma_addr < dma_addr_base + size; s = sg_next(s)) { 458 pa = page_to_phys(sg_page(s)); 459 ret = __dma_update_trans(zdev, pa, dma_addr, 460 s->offset + s->length, flags); 461 if (ret) 462 goto unmap; 463 464 dma_addr += s->offset + s->length; 465 } 466 ret = __dma_purge_tlb(zdev, dma_addr_base, size, flags); 467 if (ret) 468 goto unmap; 469 470 *handle = dma_addr_base; 471 atomic64_add(nr_pages, &zdev->mapped_pages); 472 473 return ret; 474 475 unmap: 476 dma_update_trans(zdev, 0, dma_addr_base, dma_addr - dma_addr_base, 477 ZPCI_PTE_INVALID); 478 dma_free_address(dev, dma_addr_base, nr_pages); 479 zpci_err("map error:\n"); 480 zpci_err_dma(ret, pa); 481 return ret; 482 } 483 484 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg, 485 int nr_elements, enum dma_data_direction dir, 486 unsigned long attrs) 487 { 488 struct scatterlist *s = sg, *start = sg, *dma = sg; 489 unsigned int max = dma_get_max_seg_size(dev); 490 unsigned int size = s->offset + s->length; 491 unsigned int offset = s->offset; 492 int count = 0, i, ret; 493 494 for (i = 1; i < nr_elements; i++) { 495 s = sg_next(s); 496 497 s->dma_length = 0; 498 499 if (s->offset || (size & ~PAGE_MASK) || 500 size + s->length > max) { 501 ret = __s390_dma_map_sg(dev, start, size, 502 &dma->dma_address, dir); 503 if (ret) 504 goto unmap; 505 506 dma->dma_address += offset; 507 dma->dma_length = size - offset; 508 509 size = offset = s->offset; 510 start = s; 511 dma = sg_next(dma); 512 count++; 513 } 514 size += s->length; 515 } 516 ret = __s390_dma_map_sg(dev, start, size, &dma->dma_address, dir); 517 if (ret) 518 goto unmap; 519 520 dma->dma_address += offset; 521 dma->dma_length = size - offset; 522 523 return count + 1; 524 unmap: 525 for_each_sg(sg, s, count, i) 526 s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s), 527 dir, attrs); 528 529 return ret; 530 } 531 532 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg, 533 int nr_elements, enum dma_data_direction dir, 534 unsigned long attrs) 535 { 536 struct scatterlist *s; 537 int i; 538 539 for_each_sg(sg, s, nr_elements, i) { 540 if (s->dma_length) 541 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, 542 dir, attrs); 543 s->dma_address = 0; 544 s->dma_length = 0; 545 } 546 } 547 548 int zpci_dma_init_device(struct zpci_dev *zdev) 549 { 550 int rc; 551 552 /* 553 * At this point, if the device is part of an IOMMU domain, this would 554 * be a strong hint towards a bug in the IOMMU API (common) code and/or 555 * simultaneous access via IOMMU and DMA API. So let's issue a warning. 556 */ 557 WARN_ON(zdev->s390_domain); 558 559 spin_lock_init(&zdev->iommu_bitmap_lock); 560 spin_lock_init(&zdev->dma_table_lock); 561 562 zdev->dma_table = dma_alloc_cpu_table(); 563 if (!zdev->dma_table) { 564 rc = -ENOMEM; 565 goto out; 566 } 567 568 /* 569 * Restrict the iommu bitmap size to the minimum of the following: 570 * - s390_iommu_aperture which defaults to high_memory 571 * - 3-level pagetable address limit minus start_dma offset 572 * - DMA address range allowed by the hardware (clp query pci fn) 573 * 574 * Also set zdev->end_dma to the actual end address of the usable 575 * range, instead of the theoretical maximum as reported by hardware. 576 * 577 * This limits the number of concurrently usable DMA mappings since 578 * for each DMA mapped memory address we need a DMA address including 579 * extra DMA addresses for multiple mappings of the same memory address. 580 */ 581 zdev->start_dma = PAGE_ALIGN(zdev->start_dma); 582 zdev->iommu_size = min3(s390_iommu_aperture, 583 ZPCI_TABLE_SIZE_RT - zdev->start_dma, 584 zdev->end_dma - zdev->start_dma + 1); 585 zdev->end_dma = zdev->start_dma + zdev->iommu_size - 1; 586 zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT; 587 zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8); 588 if (!zdev->iommu_bitmap) { 589 rc = -ENOMEM; 590 goto free_dma_table; 591 } 592 if (!s390_iommu_strict) { 593 zdev->lazy_bitmap = vzalloc(zdev->iommu_pages / 8); 594 if (!zdev->lazy_bitmap) { 595 rc = -ENOMEM; 596 goto free_bitmap; 597 } 598 599 } 600 if (zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, 601 virt_to_phys(zdev->dma_table))) { 602 rc = -EIO; 603 goto free_bitmap; 604 } 605 606 return 0; 607 free_bitmap: 608 vfree(zdev->iommu_bitmap); 609 zdev->iommu_bitmap = NULL; 610 vfree(zdev->lazy_bitmap); 611 zdev->lazy_bitmap = NULL; 612 free_dma_table: 613 dma_free_cpu_table(zdev->dma_table); 614 zdev->dma_table = NULL; 615 out: 616 return rc; 617 } 618 619 int zpci_dma_exit_device(struct zpci_dev *zdev) 620 { 621 int cc = 0; 622 623 /* 624 * At this point, if the device is part of an IOMMU domain, this would 625 * be a strong hint towards a bug in the IOMMU API (common) code and/or 626 * simultaneous access via IOMMU and DMA API. So let's issue a warning. 627 */ 628 WARN_ON(zdev->s390_domain); 629 if (zdev_enabled(zdev)) 630 cc = zpci_unregister_ioat(zdev, 0); 631 /* 632 * cc == 3 indicates the function is gone already. This can happen 633 * if the function was deconfigured/disabled suddenly and we have not 634 * received a new handle yet. 635 */ 636 if (cc && cc != 3) 637 return -EIO; 638 639 dma_cleanup_tables(zdev->dma_table); 640 zdev->dma_table = NULL; 641 vfree(zdev->iommu_bitmap); 642 zdev->iommu_bitmap = NULL; 643 vfree(zdev->lazy_bitmap); 644 zdev->lazy_bitmap = NULL; 645 zdev->next_bit = 0; 646 return 0; 647 } 648 649 static int __init dma_alloc_cpu_table_caches(void) 650 { 651 dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables", 652 ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN, 653 0, NULL); 654 if (!dma_region_table_cache) 655 return -ENOMEM; 656 657 dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables", 658 ZPCI_PT_SIZE, ZPCI_PT_ALIGN, 659 0, NULL); 660 if (!dma_page_table_cache) { 661 kmem_cache_destroy(dma_region_table_cache); 662 return -ENOMEM; 663 } 664 return 0; 665 } 666 667 int __init zpci_dma_init(void) 668 { 669 s390_iommu_aperture = (u64)virt_to_phys(high_memory); 670 if (!s390_iommu_aperture_factor) 671 s390_iommu_aperture = ULONG_MAX; 672 else 673 s390_iommu_aperture *= s390_iommu_aperture_factor; 674 675 return dma_alloc_cpu_table_caches(); 676 } 677 678 void zpci_dma_exit(void) 679 { 680 kmem_cache_destroy(dma_page_table_cache); 681 kmem_cache_destroy(dma_region_table_cache); 682 } 683 684 const struct dma_map_ops s390_pci_dma_ops = { 685 .alloc = s390_dma_alloc, 686 .free = s390_dma_free, 687 .map_sg = s390_dma_map_sg, 688 .unmap_sg = s390_dma_unmap_sg, 689 .map_page = s390_dma_map_pages, 690 .unmap_page = s390_dma_unmap_pages, 691 .mmap = dma_common_mmap, 692 .get_sgtable = dma_common_get_sgtable, 693 .alloc_pages = dma_common_alloc_pages, 694 .free_pages = dma_common_free_pages, 695 /* dma_supported is unconditionally true without a callback */ 696 }; 697 EXPORT_SYMBOL_GPL(s390_pci_dma_ops); 698 699 static int __init s390_iommu_setup(char *str) 700 { 701 if (!strcmp(str, "strict")) 702 s390_iommu_strict = 1; 703 return 1; 704 } 705 706 __setup("s390_iommu=", s390_iommu_setup); 707 708 static int __init s390_iommu_aperture_setup(char *str) 709 { 710 if (kstrtou32(str, 10, &s390_iommu_aperture_factor)) 711 s390_iommu_aperture_factor = 1; 712 return 1; 713 } 714 715 __setup("s390_iommu_aperture=", s390_iommu_aperture_setup); 716