drivers/vfio/vfio_iommu_spapr_tce.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * VFIO: IOMMU DMA mapping support for TCE on POWER
   4  *
   5  * Copyright (C) 2013 IBM Corp.  All rights reserved.
   6  *     Author: Alexey Kardashevskiy <aik@ozlabs.ru>
   7  *
   8  * Derived from original vfio_iommu_type1.c:
   9  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
  10  *     Author: Alex Williamson <alex.williamson@redhat.com>
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/pci.h>
  15 #include <linux/slab.h>
  16 #include <linux/uaccess.h>
  17 #include <linux/err.h>
  18 #include <linux/vfio.h>
  19 #include <linux/vmalloc.h>
  20 #include <linux/sched/mm.h>
  21 #include <linux/sched/signal.h>
  22 #include <linux/mm.h>
  23
  24 #include <asm/iommu.h>
  25 #include <asm/tce.h>
  26 #include <asm/mmu_context.h>
  27
  28 #define DRIVER_VERSION  "0.1"
  29 #define DRIVER_AUTHOR   "aik@ozlabs.ru"
  30 #define DRIVER_DESC     "VFIO IOMMU SPAPR TCE"
  31
  32 static void tce_iommu_detach_group(void *iommu_data,
  33                 struct iommu_group *iommu_group);
  34
  35 /*
  36  * VFIO IOMMU fd for SPAPR_TCE IOMMU implementation
  37  *
  38  * This code handles mapping and unmapping of user data buffers
  39  * into DMA'ble space using the IOMMU
  40  */
  41
  42 struct tce_iommu_group {
  43         struct list_head next;
  44         struct iommu_group *grp;
  45 };
  46
  47 /*
  48  * A container needs to remember which preregistered region  it has
  49  * referenced to do proper cleanup at the userspace process exit.
  50  */
  51 struct tce_iommu_prereg {
  52         struct list_head next;
  53         struct mm_iommu_table_group_mem_t *mem;
  54 };
  55
  56 /*
  57  * The container descriptor supports only a single group per container.
  58  * Required by the API as the container is not supplied with the IOMMU group
  59  * at the moment of initialization.
  60  */
  61 struct tce_container {
  62         struct mutex lock;
  63         bool enabled;
  64         bool v2;
  65         bool def_window_pending;
  66         unsigned long locked_pages;
  67         struct mm_struct *mm;
  68         struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
  69         struct list_head group_list;
  70         struct list_head prereg_list;
  71 };
  72
  73 static long tce_iommu_mm_set(struct tce_container *container)
  74 {
  75         if (container->mm) {
  76                 if (container->mm == current->mm)
  77                         return 0;
  78                 return -EPERM;
  79         }
  80         BUG_ON(!current->mm);
  81         container->mm = current->mm;
  82         atomic_inc(&container->mm->mm_count);
  83
  84         return 0;
  85 }
  86
  87 static long tce_iommu_prereg_free(struct tce_container *container,
  88                 struct tce_iommu_prereg *tcemem)
  89 {
  90         long ret;
  91
  92         ret = mm_iommu_put(container->mm, tcemem->mem);
  93         if (ret)
  94                 return ret;
  95
  96         list_del(&tcemem->next);
  97         kfree(tcemem);
  98
  99         return 0;
 100 }
 101
 102 static long tce_iommu_unregister_pages(struct tce_container *container,
 103                 __u64 vaddr, __u64 size)
 104 {
 105         struct mm_iommu_table_group_mem_t *mem;
 106         struct tce_iommu_prereg *tcemem;
 107         bool found = false;
 108         long ret;
 109
 110         if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
 111                 return -EINVAL;
 112
 113         mem = mm_iommu_get(container->mm, vaddr, size >> PAGE_SHIFT);
 114         if (!mem)
 115                 return -ENOENT;
 116
 117         list_for_each_entry(tcemem, &container->prereg_list, next) {
 118                 if (tcemem->mem == mem) {
 119                         found = true;
 120                         break;
 121                 }
 122         }
 123
 124         if (!found)
 125                 ret = -ENOENT;
 126         else
 127                 ret = tce_iommu_prereg_free(container, tcemem);
 128
 129         mm_iommu_put(container->mm, mem);
 130
 131         return ret;
 132 }
 133
 134 static long tce_iommu_register_pages(struct tce_container *container,
 135                 __u64 vaddr, __u64 size)
 136 {
 137         long ret = 0;
 138         struct mm_iommu_table_group_mem_t *mem = NULL;
 139         struct tce_iommu_prereg *tcemem;
 140         unsigned long entries = size >> PAGE_SHIFT;
 141
 142         if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
 143                         ((vaddr + size) < vaddr))
 144                 return -EINVAL;
 145
 146         mem = mm_iommu_get(container->mm, vaddr, entries);
 147         if (mem) {
 148                 list_for_each_entry(tcemem, &container->prereg_list, next) {
 149                         if (tcemem->mem == mem) {
 150                                 ret = -EBUSY;
 151                                 goto put_exit;
 152                         }
 153                 }
 154         } else {
 155                 ret = mm_iommu_new(container->mm, vaddr, entries, &mem);
 156                 if (ret)
 157                         return ret;
 158         }
 159
 160         tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL);
 161         if (!tcemem) {
 162                 ret = -ENOMEM;
 163                 goto put_exit;
 164         }
 165
 166         tcemem->mem = mem;
 167         list_add(&tcemem->next, &container->prereg_list);
 168
 169         container->enabled = true;
 170
 171         return 0;
 172
 173 put_exit:
 174         mm_iommu_put(container->mm, mem);
 175         return ret;
 176 }
 177
 178 static bool tce_page_is_contained(struct mm_struct *mm, unsigned long hpa,
 179                 unsigned int page_shift)
 180 {
 181         struct page *page;
 182         unsigned long size = 0;
 183
 184         if (mm_iommu_is_devmem(mm, hpa, page_shift, &size))
 185                 return size == (1UL << page_shift);
 186
 187         page = pfn_to_page(hpa >> PAGE_SHIFT);
 188         /*
 189          * Check that the TCE table granularity is not bigger than the size of
 190          * a page we just found. Otherwise the hardware can get access to
 191          * a bigger memory chunk that it should.
 192          */
 193         return (PAGE_SHIFT + compound_order(compound_head(page))) >= page_shift;
 194 }
 195
 196 static inline bool tce_groups_attached(struct tce_container *container)
 197 {
 198         return !list_empty(&container->group_list);
 199 }
 200
 201 static long tce_iommu_find_table(struct tce_container *container,
 202                 phys_addr_t ioba, struct iommu_table **ptbl)
 203 {
 204         long i;
 205
 206         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 207                 struct iommu_table *tbl = container->tables[i];
 208
 209                 if (tbl) {
 210                         unsigned long entry = ioba >> tbl->it_page_shift;
 211                         unsigned long start = tbl->it_offset;
 212                         unsigned long end = start + tbl->it_size;
 213
 214                         if ((start <= entry) && (entry < end)) {
 215                                 *ptbl = tbl;
 216                                 return i;
 217                         }
 218                 }
 219         }
 220
 221         return -1;
 222 }
 223
 224 static int tce_iommu_find_free_table(struct tce_container *container)
 225 {
 226         int i;
 227
 228         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 229                 if (!container->tables[i])
 230                         return i;
 231         }
 232
 233         return -ENOSPC;
 234 }
 235
 236 static int tce_iommu_enable(struct tce_container *container)
 237 {
 238         int ret = 0;
 239         unsigned long locked;
 240         struct iommu_table_group *table_group;
 241         struct tce_iommu_group *tcegrp;
 242
 243         if (container->enabled)
 244                 return -EBUSY;
 245
 246         /*
 247          * When userspace pages are mapped into the IOMMU, they are effectively
 248          * locked memory, so, theoretically, we need to update the accounting
 249          * of locked pages on each map and unmap.  For powerpc, the map unmap
 250          * paths can be very hot, though, and the accounting would kill
 251          * performance, especially since it would be difficult to impossible
 252          * to handle the accounting in real mode only.
 253          *
 254          * To address that, rather than precisely accounting every page, we
 255          * instead account for a worst case on locked memory when the iommu is
 256          * enabled and disabled.  The worst case upper bound on locked memory
 257          * is the size of the whole iommu window, which is usually relatively
 258          * small (compared to total memory sizes) on POWER hardware.
 259          *
 260          * Also we don't have a nice way to fail on H_PUT_TCE due to ulimits,
 261          * that would effectively kill the guest at random points, much better
 262          * enforcing the limit based on the max that the guest can map.
 263          *
 264          * Unfortunately at the moment it counts whole tables, no matter how
 265          * much memory the guest has. I.e. for 4GB guest and 4 IOMMU groups
 266          * each with 2GB DMA window, 8GB will be counted here. The reason for
 267          * this is that we cannot tell here the amount of RAM used by the guest
 268          * as this information is only available from KVM and VFIO is
 269          * KVM agnostic.
 270          *
 271          * So we do not allow enabling a container without a group attached
 272          * as there is no way to know how much we should increment
 273          * the locked_vm counter.
 274          */
 275         if (!tce_groups_attached(container))
 276                 return -ENODEV;
 277
 278         tcegrp = list_first_entry(&container->group_list,
 279                         struct tce_iommu_group, next);
 280         table_group = iommu_group_get_iommudata(tcegrp->grp);
 281         if (!table_group)
 282                 return -ENODEV;
 283
 284         if (!table_group->tce32_size)
 285                 return -EPERM;
 286
 287         ret = tce_iommu_mm_set(container);
 288         if (ret)
 289                 return ret;
 290
 291         locked = table_group->tce32_size >> PAGE_SHIFT;
 292         ret = account_locked_vm(container->mm, locked, true);
 293         if (ret)
 294                 return ret;
 295
 296         container->locked_pages = locked;
 297
 298         container->enabled = true;
 299
 300         return ret;
 301 }
 302
 303 static void tce_iommu_disable(struct tce_container *container)
 304 {
 305         if (!container->enabled)
 306                 return;
 307
 308         container->enabled = false;
 309
 310         BUG_ON(!container->mm);
 311         account_locked_vm(container->mm, container->locked_pages, false);
 312 }
 313
 314 static void *tce_iommu_open(unsigned long arg)
 315 {
 316         struct tce_container *container;
 317
 318         if ((arg != VFIO_SPAPR_TCE_IOMMU) && (arg != VFIO_SPAPR_TCE_v2_IOMMU)) {
 319                 pr_err("tce_vfio: Wrong IOMMU type\n");
 320                 return ERR_PTR(-EINVAL);
 321         }
 322
 323         container = kzalloc(sizeof(*container), GFP_KERNEL);
 324         if (!container)
 325                 return ERR_PTR(-ENOMEM);
 326
 327         mutex_init(&container->lock);
 328         INIT_LIST_HEAD_RCU(&container->group_list);
 329         INIT_LIST_HEAD_RCU(&container->prereg_list);
 330
 331         container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU;
 332
 333         return container;
 334 }
 335
 336 static int tce_iommu_clear(struct tce_container *container,
 337                 struct iommu_table *tbl,
 338                 unsigned long entry, unsigned long pages);
 339 static void tce_iommu_free_table(struct tce_container *container,
 340                 struct iommu_table *tbl);
 341
 342 static void tce_iommu_release(void *iommu_data)
 343 {
 344         struct tce_container *container = iommu_data;
 345         struct tce_iommu_group *tcegrp;
 346         struct tce_iommu_prereg *tcemem, *tmtmp;
 347         long i;
 348
 349         while (tce_groups_attached(container)) {
 350                 tcegrp = list_first_entry(&container->group_list,
 351                                 struct tce_iommu_group, next);
 352                 tce_iommu_detach_group(iommu_data, tcegrp->grp);
 353         }
 354
 355         /*
 356          * If VFIO created a table, it was not disposed
 357          * by tce_iommu_detach_group() so do it now.
 358          */
 359         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
 360                 struct iommu_table *tbl = container->tables[i];
 361
 362                 if (!tbl)
 363                         continue;
 364
 365                 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
 366                 tce_iommu_free_table(container, tbl);
 367         }
 368
 369         list_for_each_entry_safe(tcemem, tmtmp, &container->prereg_list, next)
 370                 WARN_ON(tce_iommu_prereg_free(container, tcemem));
 371
 372         tce_iommu_disable(container);
 373         if (container->mm)
 374                 mmdrop(container->mm);
 375         mutex_destroy(&container->lock);
 376
 377         kfree(container);
 378 }
 379
 380 static void tce_iommu_unuse_page(struct tce_container *container,
 381                 unsigned long hpa)
 382 {
 383         struct page *page;
 384
 385         page = pfn_to_page(hpa >> PAGE_SHIFT);
 386         put_page(page);
 387 }
 388
 389 static int tce_iommu_prereg_ua_to_hpa(struct tce_container *container,
 390                 unsigned long tce, unsigned long shift,
 391                 unsigned long *phpa, struct mm_iommu_table_group_mem_t **pmem)
 392 {
 393         long ret = 0;
 394         struct mm_iommu_table_group_mem_t *mem;
 395
 396         mem = mm_iommu_lookup(container->mm, tce, 1ULL << shift);
 397         if (!mem)
 398                 return -EINVAL;
 399
 400         ret = mm_iommu_ua_to_hpa(mem, tce, shift, phpa);
 401         if (ret)
 402                 return -EINVAL;
 403
 404         *pmem = mem;
 405
 406         return 0;
 407 }
 408
 409 static void tce_iommu_unuse_page_v2(struct tce_container *container,
 410                 struct iommu_table *tbl, unsigned long entry)
 411 {
 412         struct mm_iommu_table_group_mem_t *mem = NULL;
 413         int ret;
 414         unsigned long hpa = 0;
 415         __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry);
 416
 417         if (!pua)
 418                 return;
 419
 420         ret = tce_iommu_prereg_ua_to_hpa(container, be64_to_cpu(*pua),
 421                         tbl->it_page_shift, &hpa, &mem);
 422         if (ret)
 423                 pr_debug("%s: tce %llx at #%lx was not cached, ret=%d\n",
 424                                 __func__, be64_to_cpu(*pua), entry, ret);
 425         if (mem)
 426                 mm_iommu_mapped_dec(mem);
 427
 428         *pua = cpu_to_be64(0);
 429 }
 430
 431 static int tce_iommu_clear(struct tce_container *container,
 432                 struct iommu_table *tbl,
 433                 unsigned long entry, unsigned long pages)
 434 {
 435         unsigned long oldhpa;
 436         long ret;
 437         enum dma_data_direction direction;
 438         unsigned long lastentry = entry + pages;
 439
 440         for ( ; entry < lastentry; ++entry) {
 441                 if (tbl->it_indirect_levels && tbl->it_userspace) {
 442                         /*
 443                          * For multilevel tables, we can take a shortcut here
 444                          * and skip some TCEs as we know that the userspace
 445                          * addresses cache is a mirror of the real TCE table
 446                          * and if it is missing some indirect levels, then
 447                          * the hardware table does not have them allocated
 448                          * either and therefore does not require updating.
 449                          */
 450                         __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl,
 451                                         entry);
 452                         if (!pua) {
 453                                 /* align to level_size which is power of two */
 454                                 entry |= tbl->it_level_size - 1;
 455                                 continue;
 456                         }
 457                 }
 458
 459                 cond_resched();
 460
 461                 direction = DMA_NONE;
 462                 oldhpa = 0;
 463                 ret = iommu_tce_xchg(container->mm, tbl, entry, &oldhpa,
 464                                 &direction);
 465                 if (ret)
 466                         continue;
 467
 468                 if (direction == DMA_NONE)
 469                         continue;
 470
 471                 if (container->v2) {
 472                         tce_iommu_unuse_page_v2(container, tbl, entry);
 473                         continue;
 474                 }
 475
 476                 tce_iommu_unuse_page(container, oldhpa);
 477         }
 478
 479         return 0;
 480 }
 481
 482 static int tce_iommu_use_page(unsigned long tce, unsigned long *hpa)
 483 {
 484         struct page *page = NULL;
 485         enum dma_data_direction direction = iommu_tce_direction(tce);
 486
 487         if (get_user_pages_fast(tce & PAGE_MASK, 1,
 488                         direction != DMA_TO_DEVICE ? FOLL_WRITE : 0,
 489                         &page) != 1)
 490                 return -EFAULT;
 491
 492         *hpa = __pa((unsigned long) page_address(page));
 493
 494         return 0;
 495 }
 496
 497 static long tce_iommu_build(struct tce_container *container,
 498                 struct iommu_table *tbl,
 499                 unsigned long entry, unsigned long tce, unsigned long pages,
 500                 enum dma_data_direction direction)
 501 {
 502         long i, ret = 0;
 503         unsigned long hpa;
 504         enum dma_data_direction dirtmp;
 505
 506         for (i = 0; i < pages; ++i) {
 507                 unsigned long offset = tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
 508
 509                 ret = tce_iommu_use_page(tce, &hpa);
 510                 if (ret)
 511                         break;
 512
 513                 if (!tce_page_is_contained(container->mm, hpa,
 514                                 tbl->it_page_shift)) {
 515                         ret = -EPERM;
 516                         break;
 517                 }
 518
 519                 hpa |= offset;
 520                 dirtmp = direction;
 521                 ret = iommu_tce_xchg(container->mm, tbl, entry + i, &hpa,
 522                                 &dirtmp);
 523                 if (ret) {
 524                         tce_iommu_unuse_page(container, hpa);
 525                         pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
 526                                         __func__, entry << tbl->it_page_shift,
 527                                         tce, ret);
 528                         break;
 529                 }
 530
 531                 if (dirtmp != DMA_NONE)
 532                         tce_iommu_unuse_page(container, hpa);
 533
 534                 tce += IOMMU_PAGE_SIZE(tbl);
 535         }
 536
 537         if (ret)
 538                 tce_iommu_clear(container, tbl, entry, i);
 539
 540         return ret;
 541 }
 542
 543 static long tce_iommu_build_v2(struct tce_container *container,
 544                 struct iommu_table *tbl,
 545                 unsigned long entry, unsigned long tce, unsigned long pages,
 546                 enum dma_data_direction direction)
 547 {
 548         long i, ret = 0;
 549         unsigned long hpa;
 550         enum dma_data_direction dirtmp;
 551
 552         for (i = 0; i < pages; ++i) {
 553                 struct mm_iommu_table_group_mem_t *mem = NULL;
 554                 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry + i);
 555
 556                 ret = tce_iommu_prereg_ua_to_hpa(container,
 557                                 tce, tbl->it_page_shift, &hpa, &mem);
 558                 if (ret)
 559                         break;
 560
 561                 if (!tce_page_is_contained(container->mm, hpa,
 562                                 tbl->it_page_shift)) {
 563                         ret = -EPERM;
 564                         break;
 565                 }
 566
 567                 /* Preserve offset within IOMMU page */
 568                 hpa |= tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
 569                 dirtmp = direction;
 570
 571                 /* The registered region is being unregistered */
 572                 if (mm_iommu_mapped_inc(mem))
 573                         break;
 574
 575                 ret = iommu_tce_xchg(container->mm, tbl, entry + i, &hpa,
 576                                 &dirtmp);
 577                 if (ret) {
 578                         /* dirtmp cannot be DMA_NONE here */
 579                         tce_iommu_unuse_page_v2(container, tbl, entry + i);
 580                         pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
 581                                         __func__, entry << tbl->it_page_shift,
 582                                         tce, ret);
 583                         break;
 584                 }
 585
 586                 if (dirtmp != DMA_NONE)
 587                         tce_iommu_unuse_page_v2(container, tbl, entry + i);
 588
 589                 *pua = cpu_to_be64(tce);
 590
 591                 tce += IOMMU_PAGE_SIZE(tbl);
 592         }
 593
 594         if (ret)
 595                 tce_iommu_clear(container, tbl, entry, i);
 596
 597         return ret;
 598 }
 599
 600 static long tce_iommu_create_table(struct tce_container *container,
 601                         struct iommu_table_group *table_group,
 602                         int num,
 603                         __u32 page_shift,
 604                         __u64 window_size,
 605                         __u32 levels,
 606                         struct iommu_table **ptbl)
 607 {
 608         long ret, table_size;
 609
 610         table_size = table_group->ops->get_table_size(page_shift, window_size,
 611                         levels);
 612         if (!table_size)
 613                 return -EINVAL;
 614
 615         ret = account_locked_vm(container->mm, table_size >> PAGE_SHIFT, true);
 616         if (ret)
 617                 return ret;
 618
 619         ret = table_group->ops->create_table(table_group, num,
 620                         page_shift, window_size, levels, ptbl);
 621
 622         WARN_ON(!ret && !(*ptbl)->it_ops->free);
 623         WARN_ON(!ret && ((*ptbl)->it_allocated_size > table_size));
 624
 625         return ret;
 626 }
 627
 628 static void tce_iommu_free_table(struct tce_container *container,
 629                 struct iommu_table *tbl)
 630 {
 631         unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
 632
 633         iommu_tce_table_put(tbl);
 634         account_locked_vm(container->mm, pages, false);
 635 }
 636
 637 static long tce_iommu_create_window(struct tce_container *container,
 638                 __u32 page_shift, __u64 window_size, __u32 levels,
 639                 __u64 *start_addr)
 640 {
 641         struct tce_iommu_group *tcegrp;
 642         struct iommu_table_group *table_group;
 643         struct iommu_table *tbl = NULL;
 644         long ret, num;
 645
 646         num = tce_iommu_find_free_table(container);
 647         if (num < 0)
 648                 return num;
 649
 650         /* Get the first group for ops::create_table */
 651         tcegrp = list_first_entry(&container->group_list,
 652                         struct tce_iommu_group, next);
 653         table_group = iommu_group_get_iommudata(tcegrp->grp);
 654         if (!table_group)
 655                 return -EFAULT;
 656
 657         if (!(table_group->pgsizes & (1ULL << page_shift)))
 658                 return -EINVAL;
 659
 660         if (!table_group->ops->set_window || !table_group->ops->unset_window ||
 661                         !table_group->ops->get_table_size ||
 662                         !table_group->ops->create_table)
 663                 return -EPERM;
 664
 665         /* Create TCE table */
 666         ret = tce_iommu_create_table(container, table_group, num,
 667                         page_shift, window_size, levels, &tbl);
 668         if (ret)
 669                 return ret;
 670
 671         BUG_ON(!tbl->it_ops->free);
 672
 673         /*
 674          * Program the table to every group.
 675          * Groups have been tested for compatibility at the attach time.
 676          */
 677         list_for_each_entry(tcegrp, &container->group_list, next) {
 678                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 679
 680                 ret = table_group->ops->set_window(table_group, num, tbl);
 681                 if (ret)
 682                         goto unset_exit;
 683         }
 684
 685         container->tables[num] = tbl;
 686
 687         /* Return start address assigned by platform in create_table() */
 688         *start_addr = tbl->it_offset << tbl->it_page_shift;
 689
 690         return 0;
 691
 692 unset_exit:
 693         list_for_each_entry(tcegrp, &container->group_list, next) {
 694                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 695                 table_group->ops->unset_window(table_group, num);
 696         }
 697         tce_iommu_free_table(container, tbl);
 698
 699         return ret;
 700 }
 701
 702 static long tce_iommu_remove_window(struct tce_container *container,
 703                 __u64 start_addr)
 704 {
 705         struct iommu_table_group *table_group = NULL;
 706         struct iommu_table *tbl;
 707         struct tce_iommu_group *tcegrp;
 708         int num;
 709
 710         num = tce_iommu_find_table(container, start_addr, &tbl);
 711         if (num < 0)
 712                 return -EINVAL;
 713
 714         BUG_ON(!tbl->it_size);
 715
 716         /* Detach groups from IOMMUs */
 717         list_for_each_entry(tcegrp, &container->group_list, next) {
 718                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 719
 720                 /*
 721                  * SPAPR TCE IOMMU exposes the default DMA window to
 722                  * the guest via dma32_window_start/size of
 723                  * VFIO_IOMMU_SPAPR_TCE_GET_INFO. Some platforms allow
 724                  * the userspace to remove this window, some do not so
 725                  * here we check for the platform capability.
 726                  */
 727                 if (!table_group->ops || !table_group->ops->unset_window)
 728                         return -EPERM;
 729
 730                 table_group->ops->unset_window(table_group, num);
 731         }
 732
 733         /* Free table */
 734         tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
 735         tce_iommu_free_table(container, tbl);
 736         container->tables[num] = NULL;
 737
 738         return 0;
 739 }
 740
 741 static long tce_iommu_create_default_window(struct tce_container *container)
 742 {
 743         long ret;
 744         __u64 start_addr = 0;
 745         struct tce_iommu_group *tcegrp;
 746         struct iommu_table_group *table_group;
 747
 748         if (!container->def_window_pending)
 749                 return 0;
 750
 751         if (!tce_groups_attached(container))
 752                 return -ENODEV;
 753
 754         tcegrp = list_first_entry(&container->group_list,
 755                         struct tce_iommu_group, next);
 756         table_group = iommu_group_get_iommudata(tcegrp->grp);
 757         if (!table_group)
 758                 return -ENODEV;
 759
 760         ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K,
 761                         table_group->tce32_size, 1, &start_addr);
 762         WARN_ON_ONCE(!ret && start_addr);
 763
 764         if (!ret)
 765                 container->def_window_pending = false;
 766
 767         return ret;
 768 }
 769
 770 static long tce_iommu_ioctl(void *iommu_data,
 771                                  unsigned int cmd, unsigned long arg)
 772 {
 773         struct tce_container *container = iommu_data;
 774         unsigned long minsz, ddwsz;
 775         long ret;
 776
 777         switch (cmd) {
 778         case VFIO_CHECK_EXTENSION:
 779                 switch (arg) {
 780                 case VFIO_SPAPR_TCE_IOMMU:
 781                 case VFIO_SPAPR_TCE_v2_IOMMU:
 782                         ret = 1;
 783                         break;
 784                 default:
 785                         ret = vfio_spapr_iommu_eeh_ioctl(NULL, cmd, arg);
 786                         break;
 787                 }
 788
 789                 return (ret < 0) ? 0 : ret;
 790         }
 791
 792         /*
 793          * Sanity check to prevent one userspace from manipulating
 794          * another userspace mm.
 795          */
 796         BUG_ON(!container);
 797         if (container->mm && container->mm != current->mm)
 798                 return -EPERM;
 799
 800         switch (cmd) {
 801         case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
 802                 struct vfio_iommu_spapr_tce_info info;
 803                 struct tce_iommu_group *tcegrp;
 804                 struct iommu_table_group *table_group;
 805
 806                 if (!tce_groups_attached(container))
 807                         return -ENXIO;
 808
 809                 tcegrp = list_first_entry(&container->group_list,
 810                                 struct tce_iommu_group, next);
 811                 table_group = iommu_group_get_iommudata(tcegrp->grp);
 812
 813                 if (!table_group)
 814                         return -ENXIO;
 815
 816                 minsz = offsetofend(struct vfio_iommu_spapr_tce_info,
 817                                 dma32_window_size);
 818
 819                 if (copy_from_user(&info, (void __user *)arg, minsz))
 820                         return -EFAULT;
 821
 822                 if (info.argsz < minsz)
 823                         return -EINVAL;
 824
 825                 info.dma32_window_start = table_group->tce32_start;
 826                 info.dma32_window_size = table_group->tce32_size;
 827                 info.flags = 0;
 828                 memset(&info.ddw, 0, sizeof(info.ddw));
 829
 830                 if (table_group->max_dynamic_windows_supported &&
 831                                 container->v2) {
 832                         info.flags |= VFIO_IOMMU_SPAPR_INFO_DDW;
 833                         info.ddw.pgsizes = table_group->pgsizes;
 834                         info.ddw.max_dynamic_windows_supported =
 835                                 table_group->max_dynamic_windows_supported;
 836                         info.ddw.levels = table_group->max_levels;
 837                 }
 838
 839                 ddwsz = offsetofend(struct vfio_iommu_spapr_tce_info, ddw);
 840
 841                 if (info.argsz >= ddwsz)
 842                         minsz = ddwsz;
 843
 844                 if (copy_to_user((void __user *)arg, &info, minsz))
 845                         return -EFAULT;
 846
 847                 return 0;
 848         }
 849         case VFIO_IOMMU_MAP_DMA: {
 850                 struct vfio_iommu_type1_dma_map param;
 851                 struct iommu_table *tbl = NULL;
 852                 long num;
 853                 enum dma_data_direction direction;
 854
 855                 if (!container->enabled)
 856                         return -EPERM;
 857
 858                 minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
 859
 860                 if (copy_from_user(&param, (void __user *)arg, minsz))
 861                         return -EFAULT;
 862
 863                 if (param.argsz < minsz)
 864                         return -EINVAL;
 865
 866                 if (param.flags & ~(VFIO_DMA_MAP_FLAG_READ |
 867                                 VFIO_DMA_MAP_FLAG_WRITE))
 868                         return -EINVAL;
 869
 870                 ret = tce_iommu_create_default_window(container);
 871                 if (ret)
 872                         return ret;
 873
 874                 num = tce_iommu_find_table(container, param.iova, &tbl);
 875                 if (num < 0)
 876                         return -ENXIO;
 877
 878                 if ((param.size & ~IOMMU_PAGE_MASK(tbl)) ||
 879                                 (param.vaddr & ~IOMMU_PAGE_MASK(tbl)))
 880                         return -EINVAL;
 881
 882                 /* iova is checked by the IOMMU API */
 883                 if (param.flags & VFIO_DMA_MAP_FLAG_READ) {
 884                         if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
 885                                 direction = DMA_BIDIRECTIONAL;
 886                         else
 887                                 direction = DMA_TO_DEVICE;
 888                 } else {
 889                         if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
 890                                 direction = DMA_FROM_DEVICE;
 891                         else
 892                                 return -EINVAL;
 893                 }
 894
 895                 ret = iommu_tce_put_param_check(tbl, param.iova, param.vaddr);
 896                 if (ret)
 897                         return ret;
 898
 899                 if (container->v2)
 900                         ret = tce_iommu_build_v2(container, tbl,
 901                                         param.iova >> tbl->it_page_shift,
 902                                         param.vaddr,
 903                                         param.size >> tbl->it_page_shift,
 904                                         direction);
 905                 else
 906                         ret = tce_iommu_build(container, tbl,
 907                                         param.iova >> tbl->it_page_shift,
 908                                         param.vaddr,
 909                                         param.size >> tbl->it_page_shift,
 910                                         direction);
 911
 912                 iommu_flush_tce(tbl);
 913
 914                 return ret;
 915         }
 916         case VFIO_IOMMU_UNMAP_DMA: {
 917                 struct vfio_iommu_type1_dma_unmap param;
 918                 struct iommu_table *tbl = NULL;
 919                 long num;
 920
 921                 if (!container->enabled)
 922                         return -EPERM;
 923
 924                 minsz = offsetofend(struct vfio_iommu_type1_dma_unmap,
 925                                 size);
 926
 927                 if (copy_from_user(&param, (void __user *)arg, minsz))
 928                         return -EFAULT;
 929
 930                 if (param.argsz < minsz)
 931                         return -EINVAL;
 932
 933                 /* No flag is supported now */
 934                 if (param.flags)
 935                         return -EINVAL;
 936
 937                 ret = tce_iommu_create_default_window(container);
 938                 if (ret)
 939                         return ret;
 940
 941                 num = tce_iommu_find_table(container, param.iova, &tbl);
 942                 if (num < 0)
 943                         return -ENXIO;
 944
 945                 if (param.size & ~IOMMU_PAGE_MASK(tbl))
 946                         return -EINVAL;
 947
 948                 ret = iommu_tce_clear_param_check(tbl, param.iova, 0,
 949                                 param.size >> tbl->it_page_shift);
 950                 if (ret)
 951                         return ret;
 952
 953                 ret = tce_iommu_clear(container, tbl,
 954                                 param.iova >> tbl->it_page_shift,
 955                                 param.size >> tbl->it_page_shift);
 956                 iommu_flush_tce(tbl);
 957
 958                 return ret;
 959         }
 960         case VFIO_IOMMU_SPAPR_REGISTER_MEMORY: {
 961                 struct vfio_iommu_spapr_register_memory param;
 962
 963                 if (!container->v2)
 964                         break;
 965
 966                 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
 967                                 size);
 968
 969                 ret = tce_iommu_mm_set(container);
 970                 if (ret)
 971                         return ret;
 972
 973                 if (copy_from_user(&param, (void __user *)arg, minsz))
 974                         return -EFAULT;
 975
 976                 if (param.argsz < minsz)
 977                         return -EINVAL;
 978
 979                 /* No flag is supported now */
 980                 if (param.flags)
 981                         return -EINVAL;
 982
 983                 mutex_lock(&container->lock);
 984                 ret = tce_iommu_register_pages(container, param.vaddr,
 985                                 param.size);
 986                 mutex_unlock(&container->lock);
 987
 988                 return ret;
 989         }
 990         case VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY: {
 991                 struct vfio_iommu_spapr_register_memory param;
 992
 993                 if (!container->v2)
 994                         break;
 995
 996                 if (!container->mm)
 997                         return -EPERM;
 998
 999                 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
1000                                 size);
1001
1002                 if (copy_from_user(&param, (void __user *)arg, minsz))
1003                         return -EFAULT;
1004
1005                 if (param.argsz < minsz)
1006                         return -EINVAL;
1007
1008                 /* No flag is supported now */
1009                 if (param.flags)
1010                         return -EINVAL;
1011
1012                 mutex_lock(&container->lock);
1013                 ret = tce_iommu_unregister_pages(container, param.vaddr,
1014                                 param.size);
1015                 mutex_unlock(&container->lock);
1016
1017                 return ret;
1018         }
1019         case VFIO_IOMMU_ENABLE:
1020                 if (container->v2)
1021                         break;
1022
1023                 mutex_lock(&container->lock);
1024                 ret = tce_iommu_enable(container);
1025                 mutex_unlock(&container->lock);
1026                 return ret;
1027
1028
1029         case VFIO_IOMMU_DISABLE:
1030                 if (container->v2)
1031                         break;
1032
1033                 mutex_lock(&container->lock);
1034                 tce_iommu_disable(container);
1035                 mutex_unlock(&container->lock);
1036                 return 0;
1037
1038         case VFIO_EEH_PE_OP: {
1039                 struct tce_iommu_group *tcegrp;
1040
1041                 ret = 0;
1042                 list_for_each_entry(tcegrp, &container->group_list, next) {
1043                         ret = vfio_spapr_iommu_eeh_ioctl(tcegrp->grp,
1044                                         cmd, arg);
1045                         if (ret)
1046                                 return ret;
1047                 }
1048                 return ret;
1049         }
1050
1051         case VFIO_IOMMU_SPAPR_TCE_CREATE: {
1052                 struct vfio_iommu_spapr_tce_create create;
1053
1054                 if (!container->v2)
1055                         break;
1056
1057                 ret = tce_iommu_mm_set(container);
1058                 if (ret)
1059                         return ret;
1060
1061                 if (!tce_groups_attached(container))
1062                         return -ENXIO;
1063
1064                 minsz = offsetofend(struct vfio_iommu_spapr_tce_create,
1065                                 start_addr);
1066
1067                 if (copy_from_user(&create, (void __user *)arg, minsz))
1068                         return -EFAULT;
1069
1070                 if (create.argsz < minsz)
1071                         return -EINVAL;
1072
1073                 if (create.flags)
1074                         return -EINVAL;
1075
1076                 mutex_lock(&container->lock);
1077
1078                 ret = tce_iommu_create_default_window(container);
1079                 if (!ret)
1080                         ret = tce_iommu_create_window(container,
1081                                         create.page_shift,
1082                                         create.window_size, create.levels,
1083                                         &create.start_addr);
1084
1085                 mutex_unlock(&container->lock);
1086
1087                 if (!ret && copy_to_user((void __user *)arg, &create, minsz))
1088                         ret = -EFAULT;
1089
1090                 return ret;
1091         }
1092         case VFIO_IOMMU_SPAPR_TCE_REMOVE: {
1093                 struct vfio_iommu_spapr_tce_remove remove;
1094
1095                 if (!container->v2)
1096                         break;
1097
1098                 ret = tce_iommu_mm_set(container);
1099                 if (ret)
1100                         return ret;
1101
1102                 if (!tce_groups_attached(container))
1103                         return -ENXIO;
1104
1105                 minsz = offsetofend(struct vfio_iommu_spapr_tce_remove,
1106                                 start_addr);
1107
1108                 if (copy_from_user(&remove, (void __user *)arg, minsz))
1109                         return -EFAULT;
1110
1111                 if (remove.argsz < minsz)
1112                         return -EINVAL;
1113
1114                 if (remove.flags)
1115                         return -EINVAL;
1116
1117                 if (container->def_window_pending && !remove.start_addr) {
1118                         container->def_window_pending = false;
1119                         return 0;
1120                 }
1121
1122                 mutex_lock(&container->lock);
1123
1124                 ret = tce_iommu_remove_window(container, remove.start_addr);
1125
1126                 mutex_unlock(&container->lock);
1127
1128                 return ret;
1129         }
1130         }
1131
1132         return -ENOTTY;
1133 }
1134
1135 static void tce_iommu_release_ownership(struct tce_container *container,
1136                 struct iommu_table_group *table_group)
1137 {
1138         int i;
1139
1140         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1141                 struct iommu_table *tbl = container->tables[i];
1142
1143                 if (!tbl)
1144                         continue;
1145
1146                 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
1147                 if (tbl->it_map)
1148                         iommu_release_ownership(tbl);
1149
1150                 container->tables[i] = NULL;
1151         }
1152 }
1153
1154 static int tce_iommu_take_ownership(struct tce_container *container,
1155                 struct iommu_table_group *table_group)
1156 {
1157         int i, j, rc = 0;
1158
1159         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1160                 struct iommu_table *tbl = table_group->tables[i];
1161
1162                 if (!tbl || !tbl->it_map)
1163                         continue;
1164
1165                 rc = iommu_take_ownership(tbl);
1166                 if (rc) {
1167                         for (j = 0; j < i; ++j)
1168                                 iommu_release_ownership(
1169                                                 table_group->tables[j]);
1170
1171                         return rc;
1172                 }
1173         }
1174
1175         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1176                 container->tables[i] = table_group->tables[i];
1177
1178         return 0;
1179 }
1180
1181 static void tce_iommu_release_ownership_ddw(struct tce_container *container,
1182                 struct iommu_table_group *table_group)
1183 {
1184         long i;
1185
1186         if (!table_group->ops->unset_window) {
1187                 WARN_ON_ONCE(1);
1188                 return;
1189         }
1190
1191         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1192                 if (container->tables[i])
1193                         table_group->ops->unset_window(table_group, i);
1194
1195         table_group->ops->release_ownership(table_group);
1196 }
1197
1198 static long tce_iommu_take_ownership_ddw(struct tce_container *container,
1199                 struct iommu_table_group *table_group)
1200 {
1201         long i, ret = 0;
1202
1203         if (!table_group->ops->create_table || !table_group->ops->set_window ||
1204                         !table_group->ops->release_ownership) {
1205                 WARN_ON_ONCE(1);
1206                 return -EFAULT;
1207         }
1208
1209         table_group->ops->take_ownership(table_group);
1210
1211         /* Set all windows to the new group */
1212         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1213                 struct iommu_table *tbl = container->tables[i];
1214
1215                 if (!tbl)
1216                         continue;
1217
1218                 ret = table_group->ops->set_window(table_group, i, tbl);
1219                 if (ret)
1220                         goto release_exit;
1221         }
1222
1223         return 0;
1224
1225 release_exit:
1226         for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1227                 table_group->ops->unset_window(table_group, i);
1228
1229         table_group->ops->release_ownership(table_group);
1230
1231         return ret;
1232 }
1233
1234 static int tce_iommu_attach_group(void *iommu_data,
1235                 struct iommu_group *iommu_group)
1236 {
1237         int ret;
1238         struct tce_container *container = iommu_data;
1239         struct iommu_table_group *table_group;
1240         struct tce_iommu_group *tcegrp = NULL;
1241
1242         mutex_lock(&container->lock);
1243
1244         /* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n",
1245                         iommu_group_id(iommu_group), iommu_group); */
1246         table_group = iommu_group_get_iommudata(iommu_group);
1247         if (!table_group) {
1248                 ret = -ENODEV;
1249                 goto unlock_exit;
1250         }
1251
1252         if (tce_groups_attached(container) && (!table_group->ops ||
1253                         !table_group->ops->take_ownership ||
1254                         !table_group->ops->release_ownership)) {
1255                 ret = -EBUSY;
1256                 goto unlock_exit;
1257         }
1258
1259         /* Check if new group has the same iommu_ops (i.e. compatible) */
1260         list_for_each_entry(tcegrp, &container->group_list, next) {
1261                 struct iommu_table_group *table_group_tmp;
1262
1263                 if (tcegrp->grp == iommu_group) {
1264                         pr_warn("tce_vfio: Group %d is already attached\n",
1265                                         iommu_group_id(iommu_group));
1266                         ret = -EBUSY;
1267                         goto unlock_exit;
1268                 }
1269                 table_group_tmp = iommu_group_get_iommudata(tcegrp->grp);
1270                 if (table_group_tmp->ops->create_table !=
1271                                 table_group->ops->create_table) {
1272                         pr_warn("tce_vfio: Group %d is incompatible with group %d\n",
1273                                         iommu_group_id(iommu_group),
1274                                         iommu_group_id(tcegrp->grp));
1275                         ret = -EPERM;
1276                         goto unlock_exit;
1277                 }
1278         }
1279
1280         tcegrp = kzalloc(sizeof(*tcegrp), GFP_KERNEL);
1281         if (!tcegrp) {
1282                 ret = -ENOMEM;
1283                 goto unlock_exit;
1284         }
1285
1286         if (!table_group->ops || !table_group->ops->take_ownership ||
1287                         !table_group->ops->release_ownership) {
1288                 if (container->v2) {
1289                         ret = -EPERM;
1290                         goto unlock_exit;
1291                 }
1292                 ret = tce_iommu_take_ownership(container, table_group);
1293         } else {
1294                 if (!container->v2) {
1295                         ret = -EPERM;
1296                         goto unlock_exit;
1297                 }
1298                 ret = tce_iommu_take_ownership_ddw(container, table_group);
1299                 if (!tce_groups_attached(container) && !container->tables[0])
1300                         container->def_window_pending = true;
1301         }
1302
1303         if (!ret) {
1304                 tcegrp->grp = iommu_group;
1305                 list_add(&tcegrp->next, &container->group_list);
1306         }
1307
1308 unlock_exit:
1309         if (ret && tcegrp)
1310                 kfree(tcegrp);
1311
1312         mutex_unlock(&container->lock);
1313
1314         return ret;
1315 }
1316
1317 static void tce_iommu_detach_group(void *iommu_data,
1318                 struct iommu_group *iommu_group)
1319 {
1320         struct tce_container *container = iommu_data;
1321         struct iommu_table_group *table_group;
1322         bool found = false;
1323         struct tce_iommu_group *tcegrp;
1324
1325         mutex_lock(&container->lock);
1326
1327         list_for_each_entry(tcegrp, &container->group_list, next) {
1328                 if (tcegrp->grp == iommu_group) {
1329                         found = true;
1330                         break;
1331                 }
1332         }
1333
1334         if (!found) {
1335                 pr_warn("tce_vfio: detaching unattached group #%u\n",
1336                                 iommu_group_id(iommu_group));
1337                 goto unlock_exit;
1338         }
1339
1340         list_del(&tcegrp->next);
1341         kfree(tcegrp);
1342
1343         table_group = iommu_group_get_iommudata(iommu_group);
1344         BUG_ON(!table_group);
1345
1346         if (!table_group->ops || !table_group->ops->release_ownership)
1347                 tce_iommu_release_ownership(container, table_group);
1348         else
1349                 tce_iommu_release_ownership_ddw(container, table_group);
1350
1351 unlock_exit:
1352         mutex_unlock(&container->lock);
1353 }
1354
1355 static const struct vfio_iommu_driver_ops tce_iommu_driver_ops = {
1356         .name           = "iommu-vfio-powerpc",
1357         .owner          = THIS_MODULE,
1358         .open           = tce_iommu_open,
1359         .release        = tce_iommu_release,
1360         .ioctl          = tce_iommu_ioctl,
1361         .attach_group   = tce_iommu_attach_group,
1362         .detach_group   = tce_iommu_detach_group,
1363 };
1364
1365 static int __init tce_iommu_init(void)
1366 {
1367         return vfio_register_iommu_driver(&tce_iommu_driver_ops);
1368 }
1369
1370 static void __exit tce_iommu_cleanup(void)
1371 {
1372         vfio_unregister_iommu_driver(&tce_iommu_driver_ops);
1373 }
1374
1375 module_init(tce_iommu_init);
1376 module_exit(tce_iommu_cleanup);
1377
1378 MODULE_VERSION(DRIVER_VERSION);
1379 MODULE_LICENSE("GPL v2");
1380 MODULE_AUTHOR(DRIVER_AUTHOR);
1381 MODULE_DESCRIPTION(DRIVER_DESC);
1382