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 *rtep) 67 { 68 unsigned long old_rte, rte; 69 unsigned long *sto; 70 71 rte = READ_ONCE(*rtep); 72 if (reg_entry_isvalid(rte)) { 73 sto = get_rt_sto(rte); 74 } else { 75 sto = dma_alloc_cpu_table(); 76 if (!sto) 77 return NULL; 78 79 set_rt_sto(&rte, virt_to_phys(sto)); 80 validate_rt_entry(&rte); 81 entry_clr_protected(&rte); 82 83 old_rte = cmpxchg(rtep, ZPCI_TABLE_INVALID, rte); 84 if (old_rte != ZPCI_TABLE_INVALID) { 85 /* Somone else was faster, use theirs */ 86 dma_free_cpu_table(sto); 87 sto = get_rt_sto(old_rte); 88 } 89 } 90 return sto; 91 } 92 93 static unsigned long *dma_get_page_table_origin(unsigned long *step) 94 { 95 unsigned long old_ste, ste; 96 unsigned long *pto; 97 98 ste = READ_ONCE(*step); 99 if (reg_entry_isvalid(ste)) { 100 pto = get_st_pto(ste); 101 } else { 102 pto = dma_alloc_page_table(); 103 if (!pto) 104 return NULL; 105 set_st_pto(&ste, virt_to_phys(pto)); 106 validate_st_entry(&ste); 107 entry_clr_protected(&ste); 108 109 old_ste = cmpxchg(step, ZPCI_TABLE_INVALID, ste); 110 if (old_ste != ZPCI_TABLE_INVALID) { 111 /* Somone else was faster, use theirs */ 112 dma_free_page_table(pto); 113 pto = get_st_pto(old_ste); 114 } 115 } 116 return pto; 117 } 118 119 unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr) 120 { 121 unsigned long *sto, *pto; 122 unsigned int rtx, sx, px; 123 124 rtx = calc_rtx(dma_addr); 125 sto = dma_get_seg_table_origin(&rto[rtx]); 126 if (!sto) 127 return NULL; 128 129 sx = calc_sx(dma_addr); 130 pto = dma_get_page_table_origin(&sto[sx]); 131 if (!pto) 132 return NULL; 133 134 px = calc_px(dma_addr); 135 return &pto[px]; 136 } 137 138 void dma_update_cpu_trans(unsigned long *ptep, phys_addr_t page_addr, int flags) 139 { 140 unsigned long pte; 141 142 pte = READ_ONCE(*ptep); 143 if (flags & ZPCI_PTE_INVALID) { 144 invalidate_pt_entry(&pte); 145 } else { 146 set_pt_pfaa(&pte, page_addr); 147 validate_pt_entry(&pte); 148 } 149 150 if (flags & ZPCI_TABLE_PROTECTED) 151 entry_set_protected(&pte); 152 else 153 entry_clr_protected(&pte); 154 155 xchg(ptep, pte); 156 } 157 158 static int __dma_update_trans(struct zpci_dev *zdev, phys_addr_t pa, 159 dma_addr_t dma_addr, size_t size, int flags) 160 { 161 unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; 162 phys_addr_t page_addr = (pa & PAGE_MASK); 163 unsigned long *entry; 164 int i, rc = 0; 165 166 if (!nr_pages) 167 return -EINVAL; 168 169 if (!zdev->dma_table) 170 return -EINVAL; 171 172 for (i = 0; i < nr_pages; i++) { 173 entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr); 174 if (!entry) { 175 rc = -ENOMEM; 176 goto undo_cpu_trans; 177 } 178 dma_update_cpu_trans(entry, page_addr, flags); 179 page_addr += PAGE_SIZE; 180 dma_addr += PAGE_SIZE; 181 } 182 183 undo_cpu_trans: 184 if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) { 185 flags = ZPCI_PTE_INVALID; 186 while (i-- > 0) { 187 page_addr -= PAGE_SIZE; 188 dma_addr -= PAGE_SIZE; 189 entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr); 190 if (!entry) 191 break; 192 dma_update_cpu_trans(entry, page_addr, flags); 193 } 194 } 195 return rc; 196 } 197 198 static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr, 199 size_t size, int flags) 200 { 201 unsigned long irqflags; 202 int ret; 203 204 /* 205 * With zdev->tlb_refresh == 0, rpcit is not required to establish new 206 * translations when previously invalid translation-table entries are 207 * validated. With lazy unmap, rpcit is skipped for previously valid 208 * entries, but a global rpcit is then required before any address can 209 * be re-used, i.e. after each iommu bitmap wrap-around. 210 */ 211 if ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID) { 212 if (!zdev->tlb_refresh) 213 return 0; 214 } else { 215 if (!s390_iommu_strict) 216 return 0; 217 } 218 219 ret = zpci_refresh_trans((u64) zdev->fh << 32, dma_addr, 220 PAGE_ALIGN(size)); 221 if (ret == -ENOMEM && !s390_iommu_strict) { 222 /* enable the hypervisor to free some resources */ 223 if (zpci_refresh_global(zdev)) 224 goto out; 225 226 spin_lock_irqsave(&zdev->iommu_bitmap_lock, irqflags); 227 bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap, 228 zdev->lazy_bitmap, zdev->iommu_pages); 229 bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages); 230 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, irqflags); 231 ret = 0; 232 } 233 out: 234 return ret; 235 } 236 237 static int dma_update_trans(struct zpci_dev *zdev, phys_addr_t pa, 238 dma_addr_t dma_addr, size_t size, int flags) 239 { 240 int rc; 241 242 rc = __dma_update_trans(zdev, pa, dma_addr, size, flags); 243 if (rc) 244 return rc; 245 246 rc = __dma_purge_tlb(zdev, dma_addr, size, flags); 247 if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) 248 __dma_update_trans(zdev, pa, dma_addr, size, ZPCI_PTE_INVALID); 249 250 return rc; 251 } 252 253 void dma_free_seg_table(unsigned long entry) 254 { 255 unsigned long *sto = get_rt_sto(entry); 256 int sx; 257 258 for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++) 259 if (reg_entry_isvalid(sto[sx])) 260 dma_free_page_table(get_st_pto(sto[sx])); 261 262 dma_free_cpu_table(sto); 263 } 264 265 void dma_cleanup_tables(unsigned long *table) 266 { 267 int rtx; 268 269 if (!table) 270 return; 271 272 for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++) 273 if (reg_entry_isvalid(table[rtx])) 274 dma_free_seg_table(table[rtx]); 275 276 dma_free_cpu_table(table); 277 } 278 279 static unsigned long __dma_alloc_iommu(struct device *dev, 280 unsigned long start, int size) 281 { 282 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 283 284 return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages, 285 start, size, zdev->start_dma >> PAGE_SHIFT, 286 dma_get_seg_boundary_nr_pages(dev, PAGE_SHIFT), 287 0); 288 } 289 290 static dma_addr_t dma_alloc_address(struct device *dev, int size) 291 { 292 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 293 unsigned long offset, flags; 294 295 spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags); 296 offset = __dma_alloc_iommu(dev, zdev->next_bit, size); 297 if (offset == -1) { 298 if (!s390_iommu_strict) { 299 /* global flush before DMA addresses are reused */ 300 if (zpci_refresh_global(zdev)) 301 goto out_error; 302 303 bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap, 304 zdev->lazy_bitmap, zdev->iommu_pages); 305 bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages); 306 } 307 /* wrap-around */ 308 offset = __dma_alloc_iommu(dev, 0, size); 309 if (offset == -1) 310 goto out_error; 311 } 312 zdev->next_bit = offset + size; 313 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); 314 315 return zdev->start_dma + offset * PAGE_SIZE; 316 317 out_error: 318 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); 319 return DMA_MAPPING_ERROR; 320 } 321 322 static void dma_free_address(struct device *dev, dma_addr_t dma_addr, int size) 323 { 324 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 325 unsigned long flags, offset; 326 327 offset = (dma_addr - zdev->start_dma) >> PAGE_SHIFT; 328 329 spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags); 330 if (!zdev->iommu_bitmap) 331 goto out; 332 333 if (s390_iommu_strict) 334 bitmap_clear(zdev->iommu_bitmap, offset, size); 335 else 336 bitmap_set(zdev->lazy_bitmap, offset, size); 337 338 out: 339 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); 340 } 341 342 static inline void zpci_err_dma(unsigned long rc, unsigned long addr) 343 { 344 struct { 345 unsigned long rc; 346 unsigned long addr; 347 } __packed data = {rc, addr}; 348 349 zpci_err_hex(&data, sizeof(data)); 350 } 351 352 static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page, 353 unsigned long offset, size_t size, 354 enum dma_data_direction direction, 355 unsigned long attrs) 356 { 357 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 358 unsigned long pa = page_to_phys(page) + offset; 359 int flags = ZPCI_PTE_VALID; 360 unsigned long nr_pages; 361 dma_addr_t dma_addr; 362 int ret; 363 364 /* This rounds up number of pages based on size and offset */ 365 nr_pages = iommu_num_pages(pa, size, PAGE_SIZE); 366 dma_addr = dma_alloc_address(dev, nr_pages); 367 if (dma_addr == DMA_MAPPING_ERROR) { 368 ret = -ENOSPC; 369 goto out_err; 370 } 371 372 /* Use rounded up size */ 373 size = nr_pages * PAGE_SIZE; 374 375 if (direction == DMA_NONE || direction == DMA_TO_DEVICE) 376 flags |= ZPCI_TABLE_PROTECTED; 377 378 ret = dma_update_trans(zdev, pa, dma_addr, size, flags); 379 if (ret) 380 goto out_free; 381 382 atomic64_add(nr_pages, &zdev->mapped_pages); 383 return dma_addr + (offset & ~PAGE_MASK); 384 385 out_free: 386 dma_free_address(dev, dma_addr, nr_pages); 387 out_err: 388 zpci_err("map error:\n"); 389 zpci_err_dma(ret, pa); 390 return DMA_MAPPING_ERROR; 391 } 392 393 static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr, 394 size_t size, enum dma_data_direction direction, 395 unsigned long attrs) 396 { 397 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 398 int npages, ret; 399 400 npages = iommu_num_pages(dma_addr, size, PAGE_SIZE); 401 dma_addr = dma_addr & PAGE_MASK; 402 ret = dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE, 403 ZPCI_PTE_INVALID); 404 if (ret) { 405 zpci_err("unmap error:\n"); 406 zpci_err_dma(ret, dma_addr); 407 return; 408 } 409 410 atomic64_add(npages, &zdev->unmapped_pages); 411 dma_free_address(dev, dma_addr, npages); 412 } 413 414 static void *s390_dma_alloc(struct device *dev, size_t size, 415 dma_addr_t *dma_handle, gfp_t flag, 416 unsigned long attrs) 417 { 418 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 419 struct page *page; 420 phys_addr_t pa; 421 dma_addr_t map; 422 423 size = PAGE_ALIGN(size); 424 page = alloc_pages(flag | __GFP_ZERO, get_order(size)); 425 if (!page) 426 return NULL; 427 428 pa = page_to_phys(page); 429 map = s390_dma_map_pages(dev, page, 0, size, DMA_BIDIRECTIONAL, 0); 430 if (dma_mapping_error(dev, map)) { 431 __free_pages(page, get_order(size)); 432 return NULL; 433 } 434 435 atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages); 436 if (dma_handle) 437 *dma_handle = map; 438 return phys_to_virt(pa); 439 } 440 441 static void s390_dma_free(struct device *dev, size_t size, 442 void *vaddr, dma_addr_t dma_handle, 443 unsigned long attrs) 444 { 445 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 446 447 size = PAGE_ALIGN(size); 448 atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages); 449 s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, 0); 450 free_pages((unsigned long)vaddr, get_order(size)); 451 } 452 453 /* Map a segment into a contiguous dma address area */ 454 static int __s390_dma_map_sg(struct device *dev, struct scatterlist *sg, 455 size_t size, dma_addr_t *handle, 456 enum dma_data_direction dir) 457 { 458 unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; 459 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 460 dma_addr_t dma_addr_base, dma_addr; 461 int flags = ZPCI_PTE_VALID; 462 struct scatterlist *s; 463 phys_addr_t pa = 0; 464 int ret; 465 466 dma_addr_base = dma_alloc_address(dev, nr_pages); 467 if (dma_addr_base == DMA_MAPPING_ERROR) 468 return -ENOMEM; 469 470 dma_addr = dma_addr_base; 471 if (dir == DMA_NONE || dir == DMA_TO_DEVICE) 472 flags |= ZPCI_TABLE_PROTECTED; 473 474 for (s = sg; dma_addr < dma_addr_base + size; s = sg_next(s)) { 475 pa = page_to_phys(sg_page(s)); 476 ret = __dma_update_trans(zdev, pa, dma_addr, 477 s->offset + s->length, flags); 478 if (ret) 479 goto unmap; 480 481 dma_addr += s->offset + s->length; 482 } 483 ret = __dma_purge_tlb(zdev, dma_addr_base, size, flags); 484 if (ret) 485 goto unmap; 486 487 *handle = dma_addr_base; 488 atomic64_add(nr_pages, &zdev->mapped_pages); 489 490 return ret; 491 492 unmap: 493 dma_update_trans(zdev, 0, dma_addr_base, dma_addr - dma_addr_base, 494 ZPCI_PTE_INVALID); 495 dma_free_address(dev, dma_addr_base, nr_pages); 496 zpci_err("map error:\n"); 497 zpci_err_dma(ret, pa); 498 return ret; 499 } 500 501 static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg, 502 int nr_elements, enum dma_data_direction dir, 503 unsigned long attrs) 504 { 505 struct scatterlist *s = sg, *start = sg, *dma = sg; 506 unsigned int max = dma_get_max_seg_size(dev); 507 unsigned int size = s->offset + s->length; 508 unsigned int offset = s->offset; 509 int count = 0, i, ret; 510 511 for (i = 1; i < nr_elements; i++) { 512 s = sg_next(s); 513 514 s->dma_length = 0; 515 516 if (s->offset || (size & ~PAGE_MASK) || 517 size + s->length > max) { 518 ret = __s390_dma_map_sg(dev, start, size, 519 &dma->dma_address, dir); 520 if (ret) 521 goto unmap; 522 523 dma->dma_address += offset; 524 dma->dma_length = size - offset; 525 526 size = offset = s->offset; 527 start = s; 528 dma = sg_next(dma); 529 count++; 530 } 531 size += s->length; 532 } 533 ret = __s390_dma_map_sg(dev, start, size, &dma->dma_address, dir); 534 if (ret) 535 goto unmap; 536 537 dma->dma_address += offset; 538 dma->dma_length = size - offset; 539 540 return count + 1; 541 unmap: 542 for_each_sg(sg, s, count, i) 543 s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s), 544 dir, attrs); 545 546 return ret; 547 } 548 549 static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg, 550 int nr_elements, enum dma_data_direction dir, 551 unsigned long attrs) 552 { 553 struct scatterlist *s; 554 int i; 555 556 for_each_sg(sg, s, nr_elements, i) { 557 if (s->dma_length) 558 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, 559 dir, attrs); 560 s->dma_address = 0; 561 s->dma_length = 0; 562 } 563 } 564 565 int zpci_dma_init_device(struct zpci_dev *zdev) 566 { 567 u8 status; 568 int rc; 569 570 /* 571 * At this point, if the device is part of an IOMMU domain, this would 572 * be a strong hint towards a bug in the IOMMU API (common) code and/or 573 * simultaneous access via IOMMU and DMA API. So let's issue a warning. 574 */ 575 WARN_ON(zdev->s390_domain); 576 577 spin_lock_init(&zdev->iommu_bitmap_lock); 578 579 zdev->dma_table = dma_alloc_cpu_table(); 580 if (!zdev->dma_table) { 581 rc = -ENOMEM; 582 goto out; 583 } 584 585 /* 586 * Restrict the iommu bitmap size to the minimum of the following: 587 * - s390_iommu_aperture which defaults to high_memory 588 * - 3-level pagetable address limit minus start_dma offset 589 * - DMA address range allowed by the hardware (clp query pci fn) 590 * 591 * Also set zdev->end_dma to the actual end address of the usable 592 * range, instead of the theoretical maximum as reported by hardware. 593 * 594 * This limits the number of concurrently usable DMA mappings since 595 * for each DMA mapped memory address we need a DMA address including 596 * extra DMA addresses for multiple mappings of the same memory address. 597 */ 598 zdev->start_dma = PAGE_ALIGN(zdev->start_dma); 599 zdev->iommu_size = min3(s390_iommu_aperture, 600 ZPCI_TABLE_SIZE_RT - zdev->start_dma, 601 zdev->end_dma - zdev->start_dma + 1); 602 zdev->end_dma = zdev->start_dma + zdev->iommu_size - 1; 603 zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT; 604 zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8); 605 if (!zdev->iommu_bitmap) { 606 rc = -ENOMEM; 607 goto free_dma_table; 608 } 609 if (!s390_iommu_strict) { 610 zdev->lazy_bitmap = vzalloc(zdev->iommu_pages / 8); 611 if (!zdev->lazy_bitmap) { 612 rc = -ENOMEM; 613 goto free_bitmap; 614 } 615 616 } 617 if (zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, 618 virt_to_phys(zdev->dma_table), &status)) { 619 rc = -EIO; 620 goto free_bitmap; 621 } 622 623 return 0; 624 free_bitmap: 625 vfree(zdev->iommu_bitmap); 626 zdev->iommu_bitmap = NULL; 627 vfree(zdev->lazy_bitmap); 628 zdev->lazy_bitmap = NULL; 629 free_dma_table: 630 dma_free_cpu_table(zdev->dma_table); 631 zdev->dma_table = NULL; 632 out: 633 return rc; 634 } 635 636 int zpci_dma_exit_device(struct zpci_dev *zdev) 637 { 638 int cc = 0; 639 640 /* 641 * At this point, if the device is part of an IOMMU domain, this would 642 * be a strong hint towards a bug in the IOMMU API (common) code and/or 643 * simultaneous access via IOMMU and DMA API. So let's issue a warning. 644 */ 645 WARN_ON(zdev->s390_domain); 646 if (zdev_enabled(zdev)) 647 cc = zpci_unregister_ioat(zdev, 0); 648 /* 649 * cc == 3 indicates the function is gone already. This can happen 650 * if the function was deconfigured/disabled suddenly and we have not 651 * received a new handle yet. 652 */ 653 if (cc && cc != 3) 654 return -EIO; 655 656 dma_cleanup_tables(zdev->dma_table); 657 zdev->dma_table = NULL; 658 vfree(zdev->iommu_bitmap); 659 zdev->iommu_bitmap = NULL; 660 vfree(zdev->lazy_bitmap); 661 zdev->lazy_bitmap = NULL; 662 zdev->next_bit = 0; 663 return 0; 664 } 665 666 static int __init dma_alloc_cpu_table_caches(void) 667 { 668 dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables", 669 ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN, 670 0, NULL); 671 if (!dma_region_table_cache) 672 return -ENOMEM; 673 674 dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables", 675 ZPCI_PT_SIZE, ZPCI_PT_ALIGN, 676 0, NULL); 677 if (!dma_page_table_cache) { 678 kmem_cache_destroy(dma_region_table_cache); 679 return -ENOMEM; 680 } 681 return 0; 682 } 683 684 int __init zpci_dma_init(void) 685 { 686 s390_iommu_aperture = (u64)virt_to_phys(high_memory); 687 if (!s390_iommu_aperture_factor) 688 s390_iommu_aperture = ULONG_MAX; 689 else 690 s390_iommu_aperture *= s390_iommu_aperture_factor; 691 692 return dma_alloc_cpu_table_caches(); 693 } 694 695 void zpci_dma_exit(void) 696 { 697 kmem_cache_destroy(dma_page_table_cache); 698 kmem_cache_destroy(dma_region_table_cache); 699 } 700 701 const struct dma_map_ops s390_pci_dma_ops = { 702 .alloc = s390_dma_alloc, 703 .free = s390_dma_free, 704 .map_sg = s390_dma_map_sg, 705 .unmap_sg = s390_dma_unmap_sg, 706 .map_page = s390_dma_map_pages, 707 .unmap_page = s390_dma_unmap_pages, 708 .mmap = dma_common_mmap, 709 .get_sgtable = dma_common_get_sgtable, 710 .alloc_pages = dma_common_alloc_pages, 711 .free_pages = dma_common_free_pages, 712 /* dma_supported is unconditionally true without a callback */ 713 }; 714 EXPORT_SYMBOL_GPL(s390_pci_dma_ops); 715 716 static int __init s390_iommu_setup(char *str) 717 { 718 if (!strcmp(str, "strict")) 719 s390_iommu_strict = 1; 720 return 1; 721 } 722 723 __setup("s390_iommu=", s390_iommu_setup); 724 725 static int __init s390_iommu_aperture_setup(char *str) 726 { 727 if (kstrtou32(str, 10, &s390_iommu_aperture_factor)) 728 s390_iommu_aperture_factor = 1; 729 return 1; 730 } 731 732 __setup("s390_iommu_aperture=", s390_iommu_aperture_setup); 733