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 18static struct kmem_cache *dma_region_table_cache; 19static struct kmem_cache *dma_page_table_cache; 20static int s390_iommu_strict; 21static u64 s390_iommu_aperture; 22static u32 s390_iommu_aperture_factor = 1; 23 24static 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 30unsigned long *dma_alloc_cpu_table(gfp_t gfp) 31{ 32 unsigned long *table, *entry; 33 34 table = kmem_cache_alloc(dma_region_table_cache, gfp); 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 43static void dma_free_cpu_table(void *table) 44{ 45 kmem_cache_free(dma_region_table_cache, table); 46} 47 48static unsigned long *dma_alloc_page_table(gfp_t gfp) 49{ 50 unsigned long *table, *entry; 51 52 table = kmem_cache_alloc(dma_page_table_cache, gfp); 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 61static void dma_free_page_table(void *table) 62{ 63 kmem_cache_free(dma_page_table_cache, table); 64} 65 66static unsigned long *dma_get_seg_table_origin(unsigned long *rtep, gfp_t gfp) 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(gfp); 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 93static unsigned long *dma_get_page_table_origin(unsigned long *step, gfp_t gfp) 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(gfp); 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 119unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr, 120 gfp_t gfp) 121{ 122 unsigned long *sto, *pto; 123 unsigned int rtx, sx, px; 124 125 rtx = calc_rtx(dma_addr); 126 sto = dma_get_seg_table_origin(&rto[rtx], gfp); 127 if (!sto) 128 return NULL; 129 130 sx = calc_sx(dma_addr); 131 pto = dma_get_page_table_origin(&sto[sx], gfp); 132 if (!pto) 133 return NULL; 134 135 px = calc_px(dma_addr); 136 return &pto[px]; 137} 138 139void dma_update_cpu_trans(unsigned long *ptep, phys_addr_t page_addr, int flags) 140{ 141 unsigned long pte; 142 143 pte = READ_ONCE(*ptep); 144 if (flags & ZPCI_PTE_INVALID) { 145 invalidate_pt_entry(&pte); 146 } else { 147 set_pt_pfaa(&pte, page_addr); 148 validate_pt_entry(&pte); 149 } 150 151 if (flags & ZPCI_TABLE_PROTECTED) 152 entry_set_protected(&pte); 153 else 154 entry_clr_protected(&pte); 155 156 xchg(ptep, pte); 157} 158 159static int __dma_update_trans(struct zpci_dev *zdev, phys_addr_t pa, 160 dma_addr_t dma_addr, size_t size, int flags) 161{ 162 unsigned int nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; 163 phys_addr_t page_addr = (pa & PAGE_MASK); 164 unsigned long *entry; 165 int i, rc = 0; 166 167 if (!nr_pages) 168 return -EINVAL; 169 170 if (!zdev->dma_table) 171 return -EINVAL; 172 173 for (i = 0; i < nr_pages; i++) { 174 entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr, 175 GFP_ATOMIC); 176 if (!entry) { 177 rc = -ENOMEM; 178 goto undo_cpu_trans; 179 } 180 dma_update_cpu_trans(entry, page_addr, flags); 181 page_addr += PAGE_SIZE; 182 dma_addr += PAGE_SIZE; 183 } 184 185undo_cpu_trans: 186 if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) { 187 flags = ZPCI_PTE_INVALID; 188 while (i-- > 0) { 189 page_addr -= PAGE_SIZE; 190 dma_addr -= PAGE_SIZE; 191 entry = dma_walk_cpu_trans(zdev->dma_table, dma_addr, 192 GFP_ATOMIC); 193 if (!entry) 194 break; 195 dma_update_cpu_trans(entry, page_addr, flags); 196 } 197 } 198 return rc; 199} 200 201static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr, 202 size_t size, int flags) 203{ 204 unsigned long irqflags; 205 int ret; 206 207 /* 208 * With zdev->tlb_refresh == 0, rpcit is not required to establish new 209 * translations when previously invalid translation-table entries are 210 * validated. With lazy unmap, rpcit is skipped for previously valid 211 * entries, but a global rpcit is then required before any address can 212 * be re-used, i.e. after each iommu bitmap wrap-around. 213 */ 214 if ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID) { 215 if (!zdev->tlb_refresh) 216 return 0; 217 } else { 218 if (!s390_iommu_strict) 219 return 0; 220 } 221 222 ret = zpci_refresh_trans((u64) zdev->fh << 32, dma_addr, 223 PAGE_ALIGN(size)); 224 if (ret == -ENOMEM && !s390_iommu_strict) { 225 /* enable the hypervisor to free some resources */ 226 if (zpci_refresh_global(zdev)) 227 goto out; 228 229 spin_lock_irqsave(&zdev->iommu_bitmap_lock, irqflags); 230 bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap, 231 zdev->lazy_bitmap, zdev->iommu_pages); 232 bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages); 233 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, irqflags); 234 ret = 0; 235 } 236out: 237 return ret; 238} 239 240static int dma_update_trans(struct zpci_dev *zdev, phys_addr_t pa, 241 dma_addr_t dma_addr, size_t size, int flags) 242{ 243 int rc; 244 245 rc = __dma_update_trans(zdev, pa, dma_addr, size, flags); 246 if (rc) 247 return rc; 248 249 rc = __dma_purge_tlb(zdev, dma_addr, size, flags); 250 if (rc && ((flags & ZPCI_PTE_VALID_MASK) == ZPCI_PTE_VALID)) 251 __dma_update_trans(zdev, pa, dma_addr, size, ZPCI_PTE_INVALID); 252 253 return rc; 254} 255 256void dma_free_seg_table(unsigned long entry) 257{ 258 unsigned long *sto = get_rt_sto(entry); 259 int sx; 260 261 for (sx = 0; sx < ZPCI_TABLE_ENTRIES; sx++) 262 if (reg_entry_isvalid(sto[sx])) 263 dma_free_page_table(get_st_pto(sto[sx])); 264 265 dma_free_cpu_table(sto); 266} 267 268void dma_cleanup_tables(unsigned long *table) 269{ 270 int rtx; 271 272 if (!table) 273 return; 274 275 for (rtx = 0; rtx < ZPCI_TABLE_ENTRIES; rtx++) 276 if (reg_entry_isvalid(table[rtx])) 277 dma_free_seg_table(table[rtx]); 278 279 dma_free_cpu_table(table); 280} 281 282static unsigned long __dma_alloc_iommu(struct device *dev, 283 unsigned long start, int size) 284{ 285 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 286 287 return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages, 288 start, size, zdev->start_dma >> PAGE_SHIFT, 289 dma_get_seg_boundary_nr_pages(dev, PAGE_SHIFT), 290 0); 291} 292 293static dma_addr_t dma_alloc_address(struct device *dev, int size) 294{ 295 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 296 unsigned long offset, flags; 297 298 spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags); 299 offset = __dma_alloc_iommu(dev, zdev->next_bit, size); 300 if (offset == -1) { 301 if (!s390_iommu_strict) { 302 /* global flush before DMA addresses are reused */ 303 if (zpci_refresh_global(zdev)) 304 goto out_error; 305 306 bitmap_andnot(zdev->iommu_bitmap, zdev->iommu_bitmap, 307 zdev->lazy_bitmap, zdev->iommu_pages); 308 bitmap_zero(zdev->lazy_bitmap, zdev->iommu_pages); 309 } 310 /* wrap-around */ 311 offset = __dma_alloc_iommu(dev, 0, size); 312 if (offset == -1) 313 goto out_error; 314 } 315 zdev->next_bit = offset + size; 316 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); 317 318 return zdev->start_dma + offset * PAGE_SIZE; 319 320out_error: 321 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); 322 return DMA_MAPPING_ERROR; 323} 324 325static void dma_free_address(struct device *dev, dma_addr_t dma_addr, int size) 326{ 327 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 328 unsigned long flags, offset; 329 330 offset = (dma_addr - zdev->start_dma) >> PAGE_SHIFT; 331 332 spin_lock_irqsave(&zdev->iommu_bitmap_lock, flags); 333 if (!zdev->iommu_bitmap) 334 goto out; 335 336 if (s390_iommu_strict) 337 bitmap_clear(zdev->iommu_bitmap, offset, size); 338 else 339 bitmap_set(zdev->lazy_bitmap, offset, size); 340 341out: 342 spin_unlock_irqrestore(&zdev->iommu_bitmap_lock, flags); 343} 344 345static inline void zpci_err_dma(unsigned long rc, unsigned long addr) 346{ 347 struct { 348 unsigned long rc; 349 unsigned long addr; 350 } __packed data = {rc, addr}; 351 352 zpci_err_hex(&data, sizeof(data)); 353} 354 355static dma_addr_t s390_dma_map_pages(struct device *dev, struct page *page, 356 unsigned long offset, size_t size, 357 enum dma_data_direction direction, 358 unsigned long attrs) 359{ 360 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 361 unsigned long pa = page_to_phys(page) + offset; 362 int flags = ZPCI_PTE_VALID; 363 unsigned long nr_pages; 364 dma_addr_t dma_addr; 365 int ret; 366 367 /* This rounds up number of pages based on size and offset */ 368 nr_pages = iommu_num_pages(pa, size, PAGE_SIZE); 369 dma_addr = dma_alloc_address(dev, nr_pages); 370 if (dma_addr == DMA_MAPPING_ERROR) { 371 ret = -ENOSPC; 372 goto out_err; 373 } 374 375 /* Use rounded up size */ 376 size = nr_pages * PAGE_SIZE; 377 378 if (direction == DMA_NONE || direction == DMA_TO_DEVICE) 379 flags |= ZPCI_TABLE_PROTECTED; 380 381 ret = dma_update_trans(zdev, pa, dma_addr, size, flags); 382 if (ret) 383 goto out_free; 384 385 atomic64_add(nr_pages, &zdev->mapped_pages); 386 return dma_addr + (offset & ~PAGE_MASK); 387 388out_free: 389 dma_free_address(dev, dma_addr, nr_pages); 390out_err: 391 zpci_err("map error:\n"); 392 zpci_err_dma(ret, pa); 393 return DMA_MAPPING_ERROR; 394} 395 396static void s390_dma_unmap_pages(struct device *dev, dma_addr_t dma_addr, 397 size_t size, enum dma_data_direction direction, 398 unsigned long attrs) 399{ 400 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 401 int npages, ret; 402 403 npages = iommu_num_pages(dma_addr, size, PAGE_SIZE); 404 dma_addr = dma_addr & PAGE_MASK; 405 ret = dma_update_trans(zdev, 0, dma_addr, npages * PAGE_SIZE, 406 ZPCI_PTE_INVALID); 407 if (ret) { 408 zpci_err("unmap error:\n"); 409 zpci_err_dma(ret, dma_addr); 410 return; 411 } 412 413 atomic64_add(npages, &zdev->unmapped_pages); 414 dma_free_address(dev, dma_addr, npages); 415} 416 417static void *s390_dma_alloc(struct device *dev, size_t size, 418 dma_addr_t *dma_handle, gfp_t flag, 419 unsigned long attrs) 420{ 421 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 422 struct page *page; 423 phys_addr_t pa; 424 dma_addr_t map; 425 426 size = PAGE_ALIGN(size); 427 page = alloc_pages(flag | __GFP_ZERO, get_order(size)); 428 if (!page) 429 return NULL; 430 431 pa = page_to_phys(page); 432 map = s390_dma_map_pages(dev, page, 0, size, DMA_BIDIRECTIONAL, 0); 433 if (dma_mapping_error(dev, map)) { 434 __free_pages(page, get_order(size)); 435 return NULL; 436 } 437 438 atomic64_add(size / PAGE_SIZE, &zdev->allocated_pages); 439 if (dma_handle) 440 *dma_handle = map; 441 return phys_to_virt(pa); 442} 443 444static void s390_dma_free(struct device *dev, size_t size, 445 void *vaddr, dma_addr_t dma_handle, 446 unsigned long attrs) 447{ 448 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 449 450 size = PAGE_ALIGN(size); 451 atomic64_sub(size / PAGE_SIZE, &zdev->allocated_pages); 452 s390_dma_unmap_pages(dev, dma_handle, size, DMA_BIDIRECTIONAL, 0); 453 free_pages((unsigned long)vaddr, get_order(size)); 454} 455 456/* Map a segment into a contiguous dma address area */ 457static int __s390_dma_map_sg(struct device *dev, struct scatterlist *sg, 458 size_t size, dma_addr_t *handle, 459 enum dma_data_direction dir) 460{ 461 unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; 462 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 463 dma_addr_t dma_addr_base, dma_addr; 464 int flags = ZPCI_PTE_VALID; 465 struct scatterlist *s; 466 phys_addr_t pa = 0; 467 int ret; 468 469 dma_addr_base = dma_alloc_address(dev, nr_pages); 470 if (dma_addr_base == DMA_MAPPING_ERROR) 471 return -ENOMEM; 472 473 dma_addr = dma_addr_base; 474 if (dir == DMA_NONE || dir == DMA_TO_DEVICE) 475 flags |= ZPCI_TABLE_PROTECTED; 476 477 for (s = sg; dma_addr < dma_addr_base + size; s = sg_next(s)) { 478 pa = page_to_phys(sg_page(s)); 479 ret = __dma_update_trans(zdev, pa, dma_addr, 480 s->offset + s->length, flags); 481 if (ret) 482 goto unmap; 483 484 dma_addr += s->offset + s->length; 485 } 486 ret = __dma_purge_tlb(zdev, dma_addr_base, size, flags); 487 if (ret) 488 goto unmap; 489 490 *handle = dma_addr_base; 491 atomic64_add(nr_pages, &zdev->mapped_pages); 492 493 return ret; 494 495unmap: 496 dma_update_trans(zdev, 0, dma_addr_base, dma_addr - dma_addr_base, 497 ZPCI_PTE_INVALID); 498 dma_free_address(dev, dma_addr_base, nr_pages); 499 zpci_err("map error:\n"); 500 zpci_err_dma(ret, pa); 501 return ret; 502} 503 504static int s390_dma_map_sg(struct device *dev, struct scatterlist *sg, 505 int nr_elements, enum dma_data_direction dir, 506 unsigned long attrs) 507{ 508 struct scatterlist *s = sg, *start = sg, *dma = sg; 509 unsigned int max = dma_get_max_seg_size(dev); 510 unsigned int size = s->offset + s->length; 511 unsigned int offset = s->offset; 512 int count = 0, i, ret; 513 514 for (i = 1; i < nr_elements; i++) { 515 s = sg_next(s); 516 517 s->dma_length = 0; 518 519 if (s->offset || (size & ~PAGE_MASK) || 520 size + s->length > max) { 521 ret = __s390_dma_map_sg(dev, start, size, 522 &dma->dma_address, dir); 523 if (ret) 524 goto unmap; 525 526 dma->dma_address += offset; 527 dma->dma_length = size - offset; 528 529 size = offset = s->offset; 530 start = s; 531 dma = sg_next(dma); 532 count++; 533 } 534 size += s->length; 535 } 536 ret = __s390_dma_map_sg(dev, start, size, &dma->dma_address, dir); 537 if (ret) 538 goto unmap; 539 540 dma->dma_address += offset; 541 dma->dma_length = size - offset; 542 543 return count + 1; 544unmap: 545 for_each_sg(sg, s, count, i) 546 s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s), 547 dir, attrs); 548 549 return ret; 550} 551 552static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg, 553 int nr_elements, enum dma_data_direction dir, 554 unsigned long attrs) 555{ 556 struct scatterlist *s; 557 int i; 558 559 for_each_sg(sg, s, nr_elements, i) { 560 if (s->dma_length) 561 s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, 562 dir, attrs); 563 s->dma_address = 0; 564 s->dma_length = 0; 565 } 566} 567 568static unsigned long *bitmap_vzalloc(size_t bits, gfp_t flags) 569{ 570 size_t n = BITS_TO_LONGS(bits); 571 size_t bytes; 572 573 if (unlikely(check_mul_overflow(n, sizeof(unsigned long), &bytes))) 574 return NULL; 575 576 return vzalloc(bytes); 577} 578 579int zpci_dma_init_device(struct zpci_dev *zdev) 580{ 581 u8 status; 582 int rc; 583 584 /* 585 * At this point, if the device is part of an IOMMU domain, this would 586 * be a strong hint towards a bug in the IOMMU API (common) code and/or 587 * simultaneous access via IOMMU and DMA API. So let's issue a warning. 588 */ 589 WARN_ON(zdev->s390_domain); 590 591 spin_lock_init(&zdev->iommu_bitmap_lock); 592 593 zdev->dma_table = dma_alloc_cpu_table(GFP_KERNEL); 594 if (!zdev->dma_table) { 595 rc = -ENOMEM; 596 goto out; 597 } 598 599 /* 600 * Restrict the iommu bitmap size to the minimum of the following: 601 * - s390_iommu_aperture which defaults to high_memory 602 * - 3-level pagetable address limit minus start_dma offset 603 * - DMA address range allowed by the hardware (clp query pci fn) 604 * 605 * Also set zdev->end_dma to the actual end address of the usable 606 * range, instead of the theoretical maximum as reported by hardware. 607 * 608 * This limits the number of concurrently usable DMA mappings since 609 * for each DMA mapped memory address we need a DMA address including 610 * extra DMA addresses for multiple mappings of the same memory address. 611 */ 612 zdev->start_dma = PAGE_ALIGN(zdev->start_dma); 613 zdev->iommu_size = min3(s390_iommu_aperture, 614 ZPCI_TABLE_SIZE_RT - zdev->start_dma, 615 zdev->end_dma - zdev->start_dma + 1); 616 zdev->end_dma = zdev->start_dma + zdev->iommu_size - 1; 617 zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT; 618 zdev->iommu_bitmap = bitmap_vzalloc(zdev->iommu_pages, GFP_KERNEL); 619 if (!zdev->iommu_bitmap) { 620 rc = -ENOMEM; 621 goto free_dma_table; 622 } 623 if (!s390_iommu_strict) { 624 zdev->lazy_bitmap = bitmap_vzalloc(zdev->iommu_pages, GFP_KERNEL); 625 if (!zdev->lazy_bitmap) { 626 rc = -ENOMEM; 627 goto free_bitmap; 628 } 629 630 } 631 if (zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, 632 virt_to_phys(zdev->dma_table), &status)) { 633 rc = -EIO; 634 goto free_bitmap; 635 } 636 637 return 0; 638free_bitmap: 639 vfree(zdev->iommu_bitmap); 640 zdev->iommu_bitmap = NULL; 641 vfree(zdev->lazy_bitmap); 642 zdev->lazy_bitmap = NULL; 643free_dma_table: 644 dma_free_cpu_table(zdev->dma_table); 645 zdev->dma_table = NULL; 646out: 647 return rc; 648} 649 650int zpci_dma_exit_device(struct zpci_dev *zdev) 651{ 652 int cc = 0; 653 654 /* 655 * At this point, if the device is part of an IOMMU domain, this would 656 * be a strong hint towards a bug in the IOMMU API (common) code and/or 657 * simultaneous access via IOMMU and DMA API. So let's issue a warning. 658 */ 659 WARN_ON(zdev->s390_domain); 660 if (zdev_enabled(zdev)) 661 cc = zpci_unregister_ioat(zdev, 0); 662 /* 663 * cc == 3 indicates the function is gone already. This can happen 664 * if the function was deconfigured/disabled suddenly and we have not 665 * received a new handle yet. 666 */ 667 if (cc && cc != 3) 668 return -EIO; 669 670 dma_cleanup_tables(zdev->dma_table); 671 zdev->dma_table = NULL; 672 vfree(zdev->iommu_bitmap); 673 zdev->iommu_bitmap = NULL; 674 vfree(zdev->lazy_bitmap); 675 zdev->lazy_bitmap = NULL; 676 zdev->next_bit = 0; 677 return 0; 678} 679 680static int __init dma_alloc_cpu_table_caches(void) 681{ 682 dma_region_table_cache = kmem_cache_create("PCI_DMA_region_tables", 683 ZPCI_TABLE_SIZE, ZPCI_TABLE_ALIGN, 684 0, NULL); 685 if (!dma_region_table_cache) 686 return -ENOMEM; 687 688 dma_page_table_cache = kmem_cache_create("PCI_DMA_page_tables", 689 ZPCI_PT_SIZE, ZPCI_PT_ALIGN, 690 0, NULL); 691 if (!dma_page_table_cache) { 692 kmem_cache_destroy(dma_region_table_cache); 693 return -ENOMEM; 694 } 695 return 0; 696} 697 698int __init zpci_dma_init(void) 699{ 700 s390_iommu_aperture = (u64)virt_to_phys(high_memory); 701 if (!s390_iommu_aperture_factor) 702 s390_iommu_aperture = ULONG_MAX; 703 else 704 s390_iommu_aperture *= s390_iommu_aperture_factor; 705 706 return dma_alloc_cpu_table_caches(); 707} 708 709void zpci_dma_exit(void) 710{ 711 kmem_cache_destroy(dma_page_table_cache); 712 kmem_cache_destroy(dma_region_table_cache); 713} 714 715const struct dma_map_ops s390_pci_dma_ops = { 716 .alloc = s390_dma_alloc, 717 .free = s390_dma_free, 718 .map_sg = s390_dma_map_sg, 719 .unmap_sg = s390_dma_unmap_sg, 720 .map_page = s390_dma_map_pages, 721 .unmap_page = s390_dma_unmap_pages, 722 .mmap = dma_common_mmap, 723 .get_sgtable = dma_common_get_sgtable, 724 .alloc_pages = dma_common_alloc_pages, 725 .free_pages = dma_common_free_pages, 726 /* dma_supported is unconditionally true without a callback */ 727}; 728EXPORT_SYMBOL_GPL(s390_pci_dma_ops); 729 730static int __init s390_iommu_setup(char *str) 731{ 732 if (!strcmp(str, "strict")) 733 s390_iommu_strict = 1; 734 return 1; 735} 736 737__setup("s390_iommu=", s390_iommu_setup); 738 739static int __init s390_iommu_aperture_setup(char *str) 740{ 741 if (kstrtou32(str, 10, &s390_iommu_aperture_factor)) 742 s390_iommu_aperture_factor = 1; 743 return 1; 744} 745 746__setup("s390_iommu_aperture=", s390_iommu_aperture_setup); 747